Amine derivative with potassium channel regulatory function, its preparation and use

ABSTRACT

The present invention provides amine derivatives represented by formula I, its isomers, racemes or optical isomers, pharmaceutical salts thereof, its amides or esters, pharmaceutical compositions containing said compounds and the preparation methods thereof. The invention also relates to the use of the above mentioned compounds in the preparation of drugs for the prophylaxis or treatment of cardiovascular diseases, diabetes, bronchial and urinary smooth muscle spasm as well as ischemic and anoxic nerve injury. The above compounds can be used to treat hypertension, angina diaphragmatic, myocardial infarction, congestive heart failure, arrhythmia, diabetes, spasmodic bronchial diseases, spasmodic bladder or ureter diseases, and depression.

FIELD OF THE INVENTION

The present invention provides an amine derivative useful as a drug forthe prophylaxis or treatment of cardiovascular diseases, diabetes,bronchial and urinary smooth muscle spasm, its stereoisomer,pharmaceutical salts, preparation methods thereof and pharmaceuticalcomposition containing said compounds. The invention relates to the useof the above mentioned compounds as a drug for prophylaxis or treatmentof cardiovascular diseases such as hypertension, arrhythmia, anginadiaphragmatic, congestive heart failure and myocardial infarction,diabetes, bronchial and urinary smooth muscle spasm. The invention alsorelates to their uses as tool drugs for the investigation of thestructure and functions of potassium channels, especially adenosinetriphosphate (ATP)-sensitive potassium channels (i.e. K_(ATP)), incardiovascular systems as well as neuronal and pancreatic cells. Thepresent invention also encompasses the use of said compounds in thetreatment of ischemic and anoxic nerve injury.

BACKGROUND OF THE INVENTION

Potassium channel is one of the important ion channels in mammalian, andhas been revealed to be involved in maintaining the membrane potentialof the excitable cells and the normal physiological functions ofhistiocytes. Compounds modulating the function of potassium channels canbe used in the clinical practice for treating the commonly encounteredand multiple cardiovascular diseases such as hypertension, anginadiaphragmatic, arrhythmia, congestive heart failure and the like,diabetes, and diseases caused by smooth muscle spasm in bronchia,bladder and ureter.

Potassium channels are mainly classified into two groups: one isvoltage-regulated potassium channel, the other is chemical-regulatedpotassium channel. Each group may be further divided into many subtypes.Using pharmacological methods to study the action properties of novelcompounds plays very important roles in elucidating the pharmacologicalcharacteristics of potassium channels and their subtypes, as well as insearching for novel and highly effective drugs for clinical therapy.

K_(ATP) is one of the chemical-regulated potassium channels. Itdistributes widely in cardiovascular systems, nerve and glands. Underpathological conditions such as ischemia or anoxia, K_(ATP) mediatesimportant pathological or physiological functions. It's an importanttarget for the evaluation of the treatment of hypertension, anginadiaphragmatic, arrhythmia, congestive heart failure, diabetes and somediseases caused by smooth muscle spasm in bronchi, bladder and ureter.

Drugs modulating potassium channels are termed as potassium channelopeners (PCO) or potassium channel activators (KCA). They are classifiedinto three types based on their physiological activities. Type-1directly acts on transition sub-units independent of both ATP andnucleoside diphosphate (NDP), including pinacidil, levcromakalim, YM-934and aprikalim, etc.; type-2 acts on sites which inhibit ATP binding orrelated sites thereof, and is dependent on ATP, including ER-001533,HOE234, etc.; type-3 acts on NDP binding sites and is dependent on NDP,such as nicorandil. Based on chemical structure, they may fall into thefollowing groups: substituted cyanoguanidines or thioureas (e.g.pinacidil, ER-001533, U-94968, BRL-49074, etc.), substituted arylamidesand derivatives thereof (e.g. nicorandil, KRN-239, Ki-1769, etc.),substituted benzopyranes and modifications thereof (e.g. levcromakalim,YM-934, Ro-31-6930, SDZ-PCO-400, UR8225, etc.), substitutedcycloalkylthioformamides (e.g. aprikalim, etc.), substituted tertiaryalcohols, dihydropyridines and their modifications, benzothiadiazines,pyrimidines and other heterocycles. Till now, there is no reports thatsecondary amines can modulate potassium channels. The antagonists ofK_(ATP) are sulfonylureas such as glyburide and gludipizide. They canantagonize the cardiovascular activities of KCAs. The major drawback ofthe reported KCAs is lack of tissue specificity and has severeside-effects such as reflex tachycardia, edema, cardialgia, flush andcardiomegalia, etc. Therefore, it is important to discover newmedicament with higher tissue specificity.

PURPOSE OF THE INVENTION

The object of the present invention is to search for and develop newdrugs for prophylaxis or treatment of cardiovascular diseases,especially for prophylaxis or treatment of the diseases related to theregulation of potassium channels.

BRIEF DESCRITION OF THE INVENTION

Through comprehensive and in-depth research, the inventors havediscovered amine derivatives represented by formula I or formula I_(a)which have potent activities of regulating potassium channels and can beuseful in prophylaxis or treatment of cardiovascular diseases, diabetes,bronchial and urinary smooth muscle spasm. It is shown that thecardiovascular actitivities (e.g. affecting blood pressure, heart rate,cardiac contraction and dilation) of amine derivatives represented byformula I or formula I_(a) can be antagonized by glyburide, anantagonist of K_(ATP). Further studies suggested that the salts resultedfrom the combination of the amine derivatives included in the inventionand inorganic acids or organic acids also have potent activities ofregulating potassium channels and they have activities of selectiveantihypertension, reduction of oxygen consumption of the heart,vasodilation, and regulation of rhythm of the heart. The invention isbased on these discoveries.

In one aspect, the invention relates to the use of an amine derivativerepresented by formula I,

its isomer, raceme or optical isomer, pharmaceutical acid additionsalts, amides or esters thereof in the preparation of the drugs usefulfor prophylaxis or treatment of cardiovascular diseases, diabetes,bronchial and urinary smooth muscle spasm. And the invention alsorelates to the uses of said compounds as the tool drugs for studying thestructure and functions of potassium channels in cardiovascular system,neuronal and pancreatic cells, especially the potassium channelssensitive to adenosine triphosphate (ATP), i.e. K_(ATP);

wherein R₁, R₂, and R₃ each independently represents hydrogen, saturatedor unsaturated, linear or branched aliphatic C₁₋₂₀, C₃₋₂₀ cycloalkyl,substituted C₃₋₂₀ cycloalkyl, C₅₋₂₀ aryl, substituted C₅₋₂₀ aryl, C₅₋₂₀heterocycloalkyl, substituted C₅₋₂₀ heterocycloalkyl, α-hydroxy C₂₋₂₀alkyl, α-C₁₋₁₀ alkylcarboxy C₁₋₁₀ alkyl, α-C₆₋₁₄ arylcarboxy C₁₋₁₀alkyl, α-substituted C₆₋₁₄ arylcarboxy C₁₋₁₀ alkyl, α-C₁₋₁₀ alkoxy C₁₋₁₀alkyl, α-substituted C₅₋₁₀ aryloxy C₁₋₁₀ alkyl, α-amino C₁₋₂₀alkyl,α-C₁₋₁₀ alkylamino C₁₋₁₀ alkyl, α-C₅₋₁₄ arylamino C₁₋₁₀ alkyl,α-substitued C₅₋₁₄ arylamino C₁₋₁₀ alkyl, α-C₁₋₁₀ alkylamido C₁₋₁₀alkyl, α-C₆₋₁₄ arylamido C₁₋₁₀ alkyl, α-substituted C₆₋₁₄ arylamidoC₁₋₁₀ alkyl;

R₄ represents hydrogen, saturated C₁₋₂₀ aliphatic alkyl, C₅₋₂₀ aryl,substituted C₅₋₂₀ aryl, C₃₋₂₀ heterocyclohydrocarbyl, substituted C₃₋₂₀heterocyclohydrocarbyl, C₃₋₂₀ heterocyclo, substituted C₃₋₂₀heterocyclo, linear C₁₋₂₀ fatty acyl, branched C₄₋₂₀ fatty acyl; orforms C₃₋₂₀ cyclohydrocarbyl or C₃₋₂₀ heterocyclo together with R₁, R₂and R₃, wherein said heterocyclo represents single or fused heterocyclocomposed of 1, 2 or 3 heteroatoms selected from nitrogen, oxygen orsulfur; The substituent of the above-mentioned groups is selecting fromthe group consisting of halogen, hydroxy, cyano, nitro, C₁₋₆ alkyl, C₁₋₆alkoxy, C₁₋₆ alkylthio, C₁₋₆ alkyl substituted with one, two or threehalogen, amino, C₁₋₁₀ hydrocarbylamino, C₁₋₁₀ hydrocarbylacyloxy, C₆₋₁₀arylacyloxy, or C₁₋₁₀ amido.

In second aspect, the invention provides a new amine derivativerepresented by formula I_(a),

its isomers, racemes or optical isomers, pharmaceutical acid additionsalts, its amides or esters, which may be useful in prophylaxis ortreatment of cardiovascular diseases, diabetes, bronchial and urinarysmooth muscle spasm; wherein,

(1) when R′₁ is isopropyl and each of R′₂ and R′₃ represents methyl, R′₄may be isopropyl, n-butyl, isobutyl, t-butyl, cyclopropylmethyl, allyl,dimethylaminoethyl, diisopropylaminoethyl; or

(2) when each of R′₁ and R′₂ represents methyl, R′₃—C—NH—R′₄ may be anamine derivative represented by the following formula I′_(a),

isomers, racemes or optical isomers thereof,

wherein each of R and R′ represents C₁₋₅ hydrocarbyl, n represents aninteger of one to eight; or

(3) when R′₁ represents phenyl, and R′₂ represents methyl, R′₃ mayrepresent methyl, ethyl or isopropyl, and R′₄ may represent propyl ormethoxycarbonyl methyl; or

(4) when R′₁ represents H₂NC(CH₃)₂—, and each of R′₂ and R′₃ representsmethyl, R′₄ represents isopropyl;

or when R′₁ represents HOC(CH₃)₂—, and each of R′₂ and R′₃ representsmethyl, R′₄ represents (CH₃)₂ CH— or (CH₃)₂CH(CH₃)—;

or when R′₁ represents 1-hydroxycyclohexyl, and each of R′₂ and R′₃represents methyl, or R′₂ and R′₃ together represent —(CH₂)₄— or—(CH₂)₅—, R′₄ represents (CH₃)₂ CH—;

or when R′₁ represents (CH₃)₂C(ONO₂)—, and each of R′₂ and R′₃represents methyl, R′₄ represents (CH₃)₂ CH—;

or when R′₁ represents

and each of R′₂ and R′₃ represents methyl, or R′₂ and R′₃ togetherrepresent —(CH₂)₄— or —(CH₂)₅—, R′₄ represents (CH₃)₂ CH—;

or when R′₁ represents

and each of R′₂ and R′₃ represents methyl, or R′₂ and R′₃ togetherrepresent —(CH₂)₄— or —(CH₂)₅—, R′₄ represents (CH₃)₂ CH—;

or when R′₁ represents

and each of R′₂ and R′₃ represents methyl, R′₄ represents (CH₃)₂ CH— or(CH₃)₂ CH(CH₃)—;

or when R′₁ represents

and each of R′₂ and R′₃ represents —(CH₂)₅—, R′₄ represents (CH₃)₂CH(CH₃)—; or

(5) when R′₁ represents cyclohexyl, and each of R′₂ and R′₃ representsmethyl, R′₄ may represent

or

when R′₁ represents cyclopentyl, and each of R′₂ and R′₃ represents—(CH₂)₂—, R′₄ may represent

or

when R′₁ represents isopropyl, and each of R′₂ and R′₃ representsmethyl, R′₄ may represent

(6) when R′₁ represents isopropyl, and each of R′₂ and R′₃ representsmethyl, R′₄ may represent Val-, Trp-, Ile-, Leu-, Phe-, O₂N-Arg-, Pro-,Leu-Val-, Trp-Trp-Trp- or (CH₃)₂ CH—SO₂—; or R₄′ may represent tosyl,nicotinyl, 4-chlorobenzoyl, morphorinoacetyl, 3-thienylacetyl, or3-indolylacetyl; or

when R′₁ represents cyclopropyl, and each of R′₂ and R′₃ represents—(CH₂)₂—, R′₄ represents Val-; or

when R′₁ represents cyclohexyl, and each of R′₂ and R′₃ representsmethyl, R′₄ represents Pro-; or

when R′₁ represents cyclohexyl, and each of R′₂ and R′₃ represents—(CH₂)₂—, R′₄ represents Pro- or nicotinyl.

In third aspect, the invention relates to an amine derivativerepresented by formula I,

its isomers, racemes or optical isomer, pharmaceutical acid additionsalts, amides or esters, which are useful for prophylaxis or treatmentof cardiovascular diseases, diabetes, bronchial and urinary smoothmuscle spasm,

wherein, R₁, R₂ and R₃ each independently represents hydrogen, saturatedor unsaturated, linear or branched C₁₋₂₀ aliphatic group, C₃₋₂₀cycloalkyl, substituted C₃₋₂₀ cycloalkyl, C₅₋₂₀ aryl, substituted C₅₋₂₀aryl, C₅₋₂₀ heterocyclohydrocarbyl, substituted C₅₋₂₀heterocyclohydrocarbyl, α-hydroxy C₂₋₂₀ alkyl, α-C₁₀ alkylcarboxy C₁₋₁₀alkyl, α-C₆₋₁₄ arylcarboxy C₁₋₁₀ alkyl, α-substituted C₆₋₁₄ arylcarboxyC₁₋₁₀ alkyl, α-C₁₋₁₀ alkoxy C₁₋₁₀ alkyl, α-substituted C₅₋₁₀ aryloxyC₁₋₁₀ alkyl, α-amino C₁₋₂₀ alkyl, α-C₁₋₁₀ alkylamino C₁₋₁₀ alkyl,α-C₅₋₁₄ arylamino C₁₋₁₀ alkyl, α-substituted C₅₋₁₄ arylamino C₁₋₁₀alkyl, α-C₁₋₁₀ alkylamido C₁₋₁₀ alkyl, α-C₆₋₁₄ arylamido C₁₋₁₀ alkyl,α-substituted C₆₋₁₄ arylamido C₁₋₁₀ alkyl;

R₄ represents hydrogen, saturated C₁₋₂₀ aliphatic alkyl, C₅₋₂₀ aryl,substituted C₅₋₂₀ aryl, C₃₋₂₀ heterocyclohydrocarbyl, substituted C₃₋₂₀heterocyclohydrocarbyl, C₃₋₂₀ heterocyclo, substituted C₃₋₂₀heterocyclo, linear C₁₋₂₀ fatty acyl, branched C₄₋₂₀ fatty acyl, orforms C₃₋₂₀ cyclohydrocarbyl or C₃₋₂₀ heterocyclo together with R₁, R₂or R₃; wherein, said heterocyclo represents single or fused heterocyclocomposed of 1, 2 or 3 heteroatoms of nitrogen, oxygen or sulfur; thesubstituent of the above-mentioned groups is selected from the groupconsisting of halogen, hydroxy, cyano, nitro, C₁₋₆ alkyl, C₁₋₆ alkoxy,C₁₋₆ alkylthio, C₁₋₆ alkyl substituted with one, two or three halogen,amino, C₁₀ hydrocarbylamino, C₁₋₁₀ hydrocarbylacyloxy, C₆₋₁₀arylacyloxy, or C₁₋₁₀ amido.

In another aspect, the invention relates to a pharmaceutical compositionwhich is composed of at least an amine derivative represented by formulaI_(a) or formula I, its isomers, racemes or optical isomers or itspharmaceutical acid addition salts, and pharmaceutical carriers orexcipients.

The invention also relates to a new method for prophylaxis or treatmentof cardiovascular diseases such as hypertension, arrhythmia, anginadiaphragmatic, congestive heart failure and myocardial infarction,diabetes, bronchial and urinary smooth muscle spasm, which includesadministering a therapeutically effective amount of an amine derivativerepresented by formula I_(a) or formula I, isomers, racemes or opticalisomer thereof to a patient suffered from a cardiovascular disease suchas hypertension, arrhythmia, angina diaphragmatic, congestive heartfailure or myocardial infarction, diabetes spasm of bronchial or urinarysmooth muscles.

The invention also relates to a process for preparation of a compoundrepresented by the above-mentioned formula I_(a) which comprisesdissolving a primary amine R′₁R′₂R′₃CNH₂ and R′₄X into an organicsolvent and heating to 50-300 degree of centigrade and/or pressurizingto 0.1-20 million pascal, wherein R′₁, R′₂, R′₃ and R′₄ are defined asabove, X represents a leaving group such as halogen and sulfonyloxy. Thereaction is carried out in the presence of a catalyst which may be anacid absorbent and/or a phase tranfer catalyst, wherein the acidabsorbent is a Lewis base including a tertiary amine or an inorganicbase, and the phase transfer catalyst is glycol or polyglycol, whereinsaid organic solvent is toluene, xylene, 1,2-dichloroethane,1,4-dioxane, dimethoxyethane, N,N-dimethylformide,N,N-dimethylacetamide, N-methylpyrrolidone, N,N-dimethylaniline orN,N-diethylaniline. The primary amine R′₁R′₂R′₃ CNH₂ is prepared byhydrolysis of hydrocarbylurea R′₁R′₂R′₃CNHCONH₂, which is manufacturedby reaction of urea with either an alkene or an alcohol of R₁′ R₂′ R₃′Cor a mixture of both in the presence of concentrated sulfuric acid and aorganic acid under 20-200 degree of centigrade, wherein said organicacid is selected from acetic acid, trifluoacetic acid or methanesulfonicacid.

The invention also provides another process for preparation of acompound represented by formula a, which comprises heating the mixtureof the primary amine R′₁R′₂R′₃CNH₂ and the aldehyde or ketone of R′₄ to30-300 degree of centigrade and/or pressurizing it to 0.1-20 millionpascal in the presence or absence of an organic solvent, wherein R′₁,R′₂, R′₃ and R′₄ are defined as above, the organic solvent are excessamount of aldehyde or ketone of R′₄, toluene, xylene,1,2-dichloroethane, 1,4-dioxane, dimethoxyethane, methanol or ethanol.The reaction is carried out in the presence of a catalyst such aspalladium carbon, Raney nickel, platinic oxide and nickel-copper.

The invention also provides another process for preparation of acompound represented by formula I_(a), which comprises reacting theenamine or Schiff base or nitrone of R′₁R′₂CNHR′₄ with an organometalliccompound R′₃M; or reducing or catalytically hydrogenating the enamine orschiff base of R₁′ R₂′ R₃′CNR₄′, wherein M is selected from the group oflithium, sodium, magnesium, aluminium and zinc.

The above-mentioned process also includes steps of preparing theisomeric compounds or optical isomers of the above-mentioned productthrough asymmetrical reaction or resolution. The process also includessteps of preparing a pharmaceutically acceptable salt by the addition ofthe above-mentioned product to an inorganic or organic acid. Examples ofthe acid addition salts are salts with inorganic acids such ashydrochloric acid, sulfuric acid, phosphoric acid and hydrobromic acid,or salts with organic acids such as acetic acid, oxalic acid, citricacid, gluconic acid, succinic acid, tartaric acid, tosylic acid,methanesulfomic acid, benzoic acid, lactic acid and maleic acid.

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the interaction of P1075, pinacidil, the compound inexample 1 (referred as compund 1 hereinafter) and glibenclamide with thebinding site in rat aortic strips labeled with [³H]P1075.

FIG. 2 shows the effects of compound 1 on potassium currents in arterysmooth muscle cells derived from rats (n=8).

FIG. 3 shows the effects of compound 1 on potassium currents in arterysmooth muscle cells derived from rats. X±SE, n=8, **P<0.01 over control.

FIG. 4 shows the effects of compound 1 on the death of normal pyramidalnerve in hippocampal CA1 region of a jird caused by cerebral ischamia.

FIG. 5 shows the effects of compound 1 on the apoptosis of normalpyramidal nerve in hippocampal CA1 region of a jird caused by cerebralischamia.

FIG. 6 shows the effects of compound 1 on grade value of symptoms innerve after cerebral apoplexy.

FIG. 7 shows the apoptosis of cordical nerve induced by low level ofoxygen and glucose, and the effects of compound 1 (under the electronicmicroscopy).

FIG. 8 shows the poptosis percentage of cordical nerve induced by lowlevel of oxygen and glucose (under flow cytometr).

DETAIL DESCRIPTION OF THE INVENTION

According to the present invention, the term of “cardiovasculardiseases” in this invention refers to, for example hypertension, anginadiaphragmatic, myocardial infarction, congestive heart failure,arrhythmiam, and so on.

According to the invention, the term “ischemic and anoxic nerve in jury”caused by conditions such as cerebral apoplexy, transient ischemiaattack, cerebral infarction, vertebro—basilar artery insufficiency,cerebral vasular dementia, hypertensive encephalopathy, cerebral edema,and cerebral trauma.

According to the present invention, for the compound represented byformula I, R₁ preferably represents tertiary butyl, cyclohexyl,cyclopentyl, cyclobutyl, cyclopropyl, isopentyl, isobutyl; or R₁represents α-substituted cyclohexyl, cyclopentyl, cyclobuty,cyclo-propyl, isohexyl, isopentyl, isobutyl or isopropyl, wherein theabove-mentioned substitutent may be amino, hydroxy, hydrocarbylamino of1 to 10 carbons, hydrocarbyloxy of 1 to 6 carbons, hydrocarbylacyloxy of1 to 10 carbons, arylacyloxy of 6 to 10 carbons and amido of 1 to 10carbons;

R₂ or R₃ preferably represents hydrogen, chained carbohydron of 1 to 12carbons or cyclic carbohydron of 3 to 8 carbons;

and R₄ preferably represents hydrogen, saturated aliphatic alkyl of 1 to20 carbons, cycloalkyl of 3 to 20 carbons, acyl of 1 to 10 carbons,C₁₋₁₀ hydrocarbylamino C₁₋₁₀ alkyl, sulfoxidyl of 1-20 carbons, aminoacid residues and lower molecule weight polypeptide thereof,β-nitrovinyl, β-cyanovinyl, substituted, carboimido, heterocyclo of 3-20carbons and heterocycloacyl of 4-20 carbons.

According to the invention, for the compound represented by formula I,more preferably, each of R₂ and R₃ represents methyl, ethyl, propyl, orR₂ and R₃ represent propylene, butylene, pentylene and hexylene.

In one preferable enbodiment of the invention, the above-mentioned R₁represents isopropyl, each of R₂ and R₃ represents methyl.

According to the invention, the compound represented by formula Ia maybe selected from the group consisting of the following compounds:

N-(1-methylethyl)-2,3-dimethyl-2-butylamine;

N-propyl-2,3-dimethyl-2-butylamine;

N-(2-methylpropyl)-2,3-dimethyl-2-butylamine;

N-cyclopropylmethyl-2,3-dimethyl-2-butylamine;

N-allyl-2,3-dimethyl-2-butylamine;

N-{2-[di(1-methylethyl)amino]ethyl}-2,3-dimethyl-2-butylamine;

N-butyl-2,3-dimethyl-2-butylamine;

N-propyl-α-methylphenylpropylamine;

N-propyl-α,β-dimethyl-phenylpropylamine;

N-(3-pyridyl)formacyl-2,3-dimethyl-2-butylamine;

N-valyl-2,3-dimethyl-2-butylamine;

N-tryptophanyl-2,3-dimethyl-2-butylamine;

N-(N-nitro)arginyl-2,3-dimethyl-2-butylamine;

N-phenylalanyl-2,3-dimethyl-2-butylamine;

N-leucyl-2,3-dimethyl-2-butylamine;

N-isoleucyl-2,3-dimethyl-2-butylamine;

N-tosyl-2,3-dimethyl-2-butylamine;

N-(1-methylethyl)-2,3-dimethyl-3-hydroxy-2-butylamine;

N-cinnamoyl-N-(1-methylethyl)-2,3-dimethyl-2-butylamine;

N-(1-methylethyl)-N-(2,4,5-trichlorophenoxyacetyl)-2,3-dimethyl-2-butylamine.

According to this invention the compound represented by formula I can bein the form of an acid addition salt. Examples of the acid addition saltare salts with inorganic acids such as hydrochloric acid, sulfuric acid,phosphoric acid, hydrobromic acid; and salts with organic acids such asacetic acid, oxalic acid, citric acid, gluconic acid, succinic acid,tartaric acid, tosylic acid, methanesulfonic acid, benzoic acid, lacticacid and maleic acid, for example,N-(1-methylethyl)-2,3-dimethyl-2-butylamine hydrochloride andN-(1-methylethyl)-2,3-dimethyl-2-butylamine tosylate.

The invention further relates to a new amine derivative represented byformula I_(a),

its isomers, racemes or optical isomers and pharmaceutical acid additionsalts, which may be useful in prophylaxis or treatment of cardiovasculardiseases, diabetes, bronchial and urinary smooth muscle spasm; wherein,

(1) when R′₁ represents isopropyl and each of R′₂ and R′₃ representsmethyl, R′₄ may be isopropyl, n-butyl, isobutyl, t-butyl,cyclopropylmethyl, allyl, dimethylaminoethyl, diisopropylaminoethyl; or

(2) when each of R′₁ and R′₂ represents methyl, R′₃—C—NH—R′₄ may be anamine derivative represented by the following formula I′_(a),

isomers, racemes or optical isomers thereof,

wherein each of R and R′ represents a hydrocarbyl group of one to fivecarbon atoms, n represents an integer of one to eight; or

(3) when R′₁ represents phenyl, and R′₂ represents methyl, R′₃represents methyl, ethyl or isopropyl, and R′₄ represents propyl ormethoxycarbonyl methyl; or

(4) when R′₁ represents H₂NC(CH₃)₂—, and each of R′₂ and R′₃ representsmethyl, R′₄ represents isopropyl;

or when R′₁ represents HOC(CH₃)₂—, and each of R′₂ and R′₃ representsmethyl, R′₄ represents (CH₃)₂CH— or (CH₃)₂ CH(CH₃)—;

or when R′₁ represents 1-hydroxycyclohexyl, and each of R′₂ and R′₃represents methyl, or R′₂ and R′₃ together represent —(CH₂)₄— or—(CH₂)₅—, R′₄ represents (CH₃)₂ CH—;

or when R′₁ represents (ONO₂)C(CH₃)₂—, and each of R′₂ and R′₃represents methyl, R′₄ represents (CH₃)₂ CH—;

or when R′₁ represents

and each of R′₂ and R′₃ represents methyl, or R′₂ and R′₃ togetherrepresent —(CH₂)₄— or —(CH₂)₅—, R′₄ represents (CH₃)₂ CH—;

or when R′₁ represents

and each of R′₂ and R′₃ represents methyl, or R′₂ and R′₃ togetherrepresent —(CH₂)₄— or —(CH₂)₅—, R′₄ represents (CH₃)₂ CH—;

or when R′₁ represents

and each of R′₂ and R′₃ represents methyl, R′₄ represents (CH₃)₂ CH— or(CH₃)₂ CH(CH₃)—;

or when R′₁ represents

and each of R′₂ and R′₃ represents —(CH₂)₅—, R′₄ represents(CH₃)₂CCH(CH₃)—; or

(5) when R′₁ represents cyclohexyl, and each of R′₂ and R′₃ representsmethyl, R′₄ may represent

or

when R′₁ represents cylclopentyl, and each of R′₂ and R′₃ represents—(CH₂)₂—, R′₄ may represent

or

when R′₁ represents isopropyl, and each of R′₂ and R′₃ representsmethyl, R′₄ may represent

or

(6) when R′₁ represents isopropyl, and each of R′₂ and R′₃ representsmethyl, R′₄ may represent Val-, Trp-, Ile-, Leu-, Phe-, O₂N-Arg-, Pro-,Leu-Val-, Trp-Trp-Trp- or (CH₃)₂ CH—SO₂—; or R₄′ may represent tosyl,nicotinyl, 4-chlorobenzoyl, morphorinoacetyl, 3-thienylacetyl, or3-indolylacetyl; or

when R′₁ represents cyclopropyl, and each of R′₂ and R′₃ represents—(CH₂)₂—, R′₄ represents Val-; or

when R′₁ represents cyclohexyl, and each of R′₂ and R′₃ representsmethyl, R′₄ represents Pro-; or

when R′₁ represents cyclohexyl, and each of R′₂ and R′₃ represents—(CH₂)₂—, R′₄ represents Pro- or nicotinyl.

According to the invention, the amine derivatives represented by formulaI_(a), its isomers, racemes or optical isomers, and its acid additionsalts are also useful in the prophylaxis or treatment of cardiovasculardiseases, diabetes, bronchial and urinary smooth muscle spasm, whereinexamples of the acid addition salts are the salts with inorganic acidssuch as hydrochloric acid, sulfuric acid, phosphoric acid, hydrobromicacid; and the salts with organic acids such as acetic acid, oxalic acid,citric acid, gluconic acid, succinic acid, tartaric acid, tosylic acid,methanesulfonic acid, benzoic acid, lactic acid, maleic acid, nicotinicacid, cinnamic acid or 3-hydroxy-3-methylglutaric acid. The preferablesalts of the amine derivative represented by formula I_(a) are saltswith hydrochloric acid, maleic acid, tosylic acid, cinnamic acid, and3-hydroxy-3-methylglutaric acid.

Specifically, for the amine derivative represented by formula I in thisinvention, each of R₁, R₂ and R₃ may or may not be the same, andindependently represents hydrogen, saturated or unsaturated, linear orbranched aliphatic hydrocarbyl of 1 to 20 carbons, C₃₋₂₀ cycloalkyl,substituted C₃₋₂₀ cycloalkyl, C₅₋₂₀ aryl, substituted C₅₋₂₀ aryl, C₅₋₂₀heterocyclohydrocarbyl, substituted C₅₋₂₀ heterocyclohydrocarbyl,α-hydroxy C₂₋₂₀ alkyl, α-C₁₋₁₀ alkylcarboxy C₁₋₁₀ alkyl, α-C₆₋₁₄arylcarboxy C₁₋₁₀ alkyl, α-substitutedC₆₋₁₄ arylcarboxy C₁₋₁₀ alkyl,α-C₁₋₁₀ alkoxy C₁₋₁₀ alkyl, α-substituted C₅₋₁₀ aryloxy C₁₋₁₀ alkyl,α-amino C₁₋₂₀ alkyl, α-C₁₋₁₀ alkylamino C₁₋₁₀ alkyl, α-C₅₋₁₄ arylaminoC₁₋₁₀ alkyl, α-substitutedC₅₋₁₄ arylamino C₁₋₁₀ alkyl, α-C₁₋₁₀alkylamido C₁₋₁₀ alkyl, α-C₆₋₁₄ arylamido C₁₋₁₀ alkyl,α-substitutedC₆₋₁₄ arylamido C₁₋₁₀ alkyl;

R₄ represents hydrogen, methyl, ethyl, n-propyl, isopropyl, substitutedcyclopropyl, substituted cyclobutyl, substituted cyclopentyl,substituted cyclohexyl, cyclopropylmethyl, cyclopentylmethyl,cyclohexylmethyl, α-(1-propenyl), 2-(1-butenyl), 3-(1-butenyl),cyclopentenyl, cyclohexenyl; or

R₄ represents aryl and substituted aryl such as phenyl, substitutedphenyl, o-nitrophenyl, m-nitrophenyl, p-nitrophenyl, 2,4-dinitrophenyl,3,5-dinitrophenyl, 2,6-dinitropheenryl; heterocyclo and substitutedheterocyclo, such as 3-pyridyl, 4-pyridyl, 3-furanyl, 3-thienyl,3-pyrrolyl, oxazolinyl, thiazolinyl, pyrazolinyl, dihydrooxazolyl,dihydrothiazolinyl, dihydropyrazolinyl, N-substituted acylpyrazolinyl,N-substituted acyldihydrooxazoliyl, N-substituted dihydropyrrolinyl,imidazolyl, substituted imidazolyl; α-substituted arylalkyl, e.g.α-substituted arylmethyl, α-substituted arylethyl, α-substitutedarylpropyl, α-substituted arylbutyl and α-substituted arylcycloalkyl; or

R₄ represents natural or unnatural amino acid residues, substitutednatural or unnatural amino acid residues, for example, Ala, Val, Leu,Ile, Phe, Asn, Glu, Trp, Tyr, Pro, Ser, Thr, Hyp, Cys, Met, Asp, Lys,Arg, His, O₂N-Arg; small peptide fragments consisting of natural orunnatural amino acid and substituted natural or unnatural amino acid,e.g. Cys-Cys, Arg-Arg-Arg, Pro-Arg-Asp, etc.; or

R₄ represents aroyl, substituted aroyl; sulfinyl, e.g. alkylsulfinylarylsulfinyl; sulfonyl e.g. alkylsulfonyl and arylsulfonyl; substitutedvinyl, e.g. α-arylamino-β-nitroethenyl and α-aryl-β-cyanoethenyl;substituted carboimidyl, e.g. N-aryl-N′-nitro-carboimidyl andN-aryl-N′-nitromethyl-carboimidyl, or

R₄ represents alkanoyl, e.g. propionyl, butanoyl and isobutanoyl etc.;heteroaroyl, e.g. 4-pyridylformyl, 3-pyrrolylacetyl, 3-indolylformyl,3-indolylacetyl, 2-pyrrolylformyl and 3-pyrrolylacetyl, etc.;substituted heteroaroyl, e.g. 4-(2-nitro)-pyridylformyl,3-(5-nitro)-pyridylformyl, 3-(5-hydroxy)-indolylformyl and3-(5-methoxy)indolylacetyl, etc.; alkylamino-alkanoyl, e.g.dimethylaminoacetyl, dimethylaminopropionyl, diethylaminoacetyl,diethylaminopropionyl, di-(isopropyl)amino-propionyl, 2-tropylformyl,2-tropenylformyl, 3-tropylformyl, 3-tropenylformyl, N-piperazinylformyl,N-benzoyl-1-piperazinylformyl, 1-tetrahydropyrrolyformyl,1-tetrahydropyrrolylacetyl, 1-tetrahydropyrrolypropionyl,1-hexahydropyridylformyl, 1-hexahydropyridylacetyl,1-tetrahydropyridylpropionyl, 1-hexahydropyridylformyl,1-hexahydropyridylacetyl, 1-hexahydropyridylpropionyl,di(cyclohexyl)-aminoacetyl, di(cyclohexyl)aminopropionyl,1-(4-hydroxy)hexahydropyridylacetyl and1-(4-hydroxy)hexahydropyridylpropionyl, etc.; alkylsulfinyl, e.g.methylsulfinyl, ethylsulfinyl, isopropylsulfinyl and N-morpholinylethylsulfinyl, etc.; alkylsulfuryl, e.g. methylsulfuryl, ethylsulfuryl,isopropylsulfuryl and N-morpholinylethylsulfuryl, etc.; arylsulfuryl,e.g. phenylsulfuryl-3-pyridylsulfuryl, 4-pyridylethylsulfuryl andp-tolylsulfuryl, etc.; α-arylamino-β-nitroethenyl, e.g.α-(3-pyridyl)amino-β-nitroethenyl, α-(4-pyridyl) amino-β-nitroethenyl,α-(6-amino-3-pyridyl)amino-β-nitroethenyl,α-(3-nitrophenyl)amino-β-nitroethenyl,α-(3-carboxyphenyl)amino-β-nitroethenyl,α-(3-cyanophenyl)amino-β-nitroethenyl,α-(3-trifluoromethylphenyl)amino-β-nitroethenyl, andα-(3,4-dihalophenyl) amino-β-nitroethenyl, etc.;α-arylamino-β-cyanoethenyl, e.g. α-(3-pyridyl)amino-β-cyanoethenyl,α-(4-pyridyl)amino-β-cyanoethenyl,α-(6-amino-3-pyridyl)amino-β-cyanoethenyl,α-(3-nitrophenyl)amino-β-cyanoethenyl,α-(3-carboxyphenyl)amino-cyanoethenyl, α-(3-cyanophenyl)amino-β-cyanoethenyl, α-(3-trifluoromethylphenyl)amino-β-cyanoethenyl,and α-(3,4-dihalophenyl)amino-β-cyanoethenyl, etc.;N-aryl-N′-nitro-carboimidyl, e.g. N-(3-pyridyl)-N′-nitro-N′-carboimidyl,N-(3-nitrophenyl) —N′-nitro-N′-carboimidyl andN-(3-halophenyl)-N′-nitro-N′-carboimidyl, etc.;N-aryl-N′-nitromethyl-carboimidyl, e.g.N-(3-pyridyl)-N′-nitromethyl-N′-carboimidyl, α-aryl-β-nitroethenyl, e.g.α-(3-pyridyl)-β-nitroethenyl, α-(4-pyridyl)-β-nitroethenyl,α-(6-amino-3-pyridyl)-β-nitroethenyl, α-(4-nitropyridyl)-β-nitroethenyl,α-(3-cyanophenyl)-β-nitroethenyl, α-(3,4-dihalophenyl)-β-nitroethenyl,ect.; α-aryl-β-cyanoethenyl, e.g. α-(3-pyridyl)-β-cyanoethenyl,α-(4-pyridyl)-β-cyanoethenyl, α-(6-amino-3-pyridyl)-β-cyanoethenyl,α-(3-nitropyridyl)-β-cyanoethenyl, α-(3-cyanophenyl)-β-cyanoethenyl,α-(3-trifluoromethylphenyl)-β-cyanoethenyl andα-(3,4-dihalophenyl)-β-cyanoethenyl; or

R₄ represents α-heterocyclo-β-nitroethenyl andα-heterocyclo-β-cyano-ethenyl, wherein the heterocyclo substituent maybe 4-benzopyranyl, 4-pyridopyranyl or 4-thienopyranyl in which position2 is substituted with 2,2-dimethyl, spiropentyl or spirohexyl; positions3 and 4 are dehydrogenated or 3-hydroxy; position 6 is substituted withan electron withdrawing group such as nitro, cyano, trifluoromethyl,pentofluoroethyl, sulfamoyl and methylsulfonyl, etc.

When R₁ represents alkyl, cycloalkyl, α-aminoalkyl, α-aminocycloalkyl oraryl, R₂ and R₃ each represents alkyl or alkylene, and R₄ representsalkyl, alkylaminoalkyl, alkenyl, cycloalkyl, alkyoxycarbonyl orarylalkyl, the preferred compound represented by formula I is shown inTable 1.

TABLE 1 the preferred compound represented by formula I wherein each ofthe substituents is hydrocarbyl compound R₁ R₂ R₃ R₄ formula 1 (CH₃)₂CH—CH₃— CH₃— (CH₃)₂CH— C₉H₂₁N 2 (CH₃)₂CH— CH₃— CH₃— H— C₆H₁₅N 3 (CH₃)₂CH—CH₃— CH₃— CH₃— C₇H₁₇N 4 (CH₃)₂CH— CH₃— CH₃— C₂H₅— C₈H₁₉N 5 (CH₃)₂CH—CH₃— CH₃— CH₃CH₂CH₂— C₉H₂₁N 6 (CH₃)₂CH— CH₃— CH₃— n-C₄H₉— C₁₀H₂₃N 7(CH₃)₂CH— CH₃— H— (CH₃)₂CH— C₈H₁₉N 8 H— H— H— (CH₃)₂CH— C₄H₁₁N 9 C₂H₅—CH₃— CH₃— (CH₃)₂CH— C₆H₁₅N 10 C₂H₅— CH₃— H— H— C₄H₁₁N 11 C₂H₅— CH₃— CH₃—CH₃— C₆H₁₅N 12 C₂H₅— CH₃— H— H— C₄H₁₁N 13 (CH₃)₂CH— CH₃— CH₃—(CH₃)₂CHCH₂— C₁₀H₂₃N 14 (CH₃)₂CH— CH₃— CH₃— t-C₄H₉— C₁₀H₂₃N 15 (CH₃)₂CH—CH₃— CH₃—

C₁₀H₂₁N 16 (CH₃)₂CH— CH₃— CH₃— (CH₃)₂NCH₂CH₂— C₁₀H₂₄N₂ 17 Ph— CH₃— CH₃—CH₃OCOCH₂— C₁₂H₁₇NO₂ 18 Ph— CH₃— C₂H₅— (CH₃)₂NCH₂CH₂— C₁₄H₂₄N₂ 19 Ph—CH₃— (CH₃)₂CH— (CH₃)₂CH— C₁₄H₂₃N 20 Ph— CH₃— CH₃— CH₃CH₂CH₂— C₁₂H₁₉N 21Ph— C₂H₅— CH₃— CH₃CH₂CH₂— C₁₃H₂₁N 22 Ph— (CH₃)₂CH— CH₃— CH₃CH₂CH₂—C₁₄H₂₃N 23 (CH₃)₂CH— CH₃— CH₃— CH₃OCOCH₂— C₉H₁₉NO₂ 24 (CH₃)₂CH— CH₃—CH₃— PhCH₂— C₁₃H₂₁N 25 (CH₃)₂CH— CH₃— CH₃— CH₂═CH—CH₂— C₉H₁₉N 26(CH₃)₂CH— CH₃— CH₃— (CH₃)₂CH—CH₂— C₁₀H₂₃N 27 (CH₃)₂CH— CH₃— CH₃—((CH₃)₂CH)₂NCH₂CH₂— C₁₄H₃₂N₂ 28

CH₃— CH₃— (CH₃)₂CH— C₁₂H₂₅N 29

CH₃— CH₃— (CH₃)₂NCH₂CH₂— C₁₃H₂₈N₂ 30

CH₃— CH₃— PhCH₂— C₁₆H₂₅N 31

CH₃— CH₃— CH₃OCOCH₂— C₁₂H₂₃NO₂ 32

—CH₂—CH₂— (CH₃)₂CH— C₉H₁₇N 33

—CH₂—CH₂— (CH₃)₂NCH₂CH₂— C₁₀H₂₀N₂ 34

—CH₂—CH₂— PhCH₂— C₁₃H₁₇N 35

—CH₂—CH₂— CH₃OCOCH₂— C₉H₁₅NO₂ 36

CH₃— CH₃— (CH₃)₂CH— C₉H₂₂N₂

When R₁ represents alkyl, cycloalkyl, α-amidoalkyl or α-amidocycloalkyl,R₂ and R₃ each represents alkyl or alkylene, and R₄ represents aminoacid residue, small peptide, sulfonyl, aroyl and heterocycloacyl, thepreferred compound represented by formula I is shown in Table 2.

TABLE 2 the preferred compound represented by formula I wherein an acylsubstituent presents in the formula compound R₁ R₂ R₃ R₄ formula 37(CH₃)₂CH— CH₃— CH₃— Val- C₁₁H₂₄N₂O 38 (CH₃)₂CH— CH₃— CH₃—

C₁₃H₂₁N₂OS 39 (CH₃)₂CH— CH₃— CH₃—

C₁₂H₂₈N₂O 40 (CH₃)₂CH— CH₃— CH₃— Trp- C₁₇H₂₅N₃O 41 (CH₃)₂CH— CH₃— CH₃—Ile- C₁₂H₂₆N₂O 42 (CH₃)₂CH— CH₃— CH₃— Leu- C₁₂H₂₆N₂O 43 (CH₃)₂CH— CH₃—CH₃— Phe- C₁₅H₂₄N₂O 44 (CH₃)₂CH— CH₃— CH₃— O₂N-Arg- C₁₂H₂₆N₆O₃ 45(CH₃)₂CH— CH₃— CH₃— Pro- C₁₁H₂₂N₂O 46 (CH₃)₂CH— CH₃— CH₃— Leu-Val-C₁₇H₃₅N₃O₂ 47

—CH₂—CH₂— Val- C₁₁H₂₀N₂O 48 (CH₃)₂CH— CH₃— CH₃— Trp-Trp-Trp- C₃₉H₄₅N₇O₃49

CH₃— CH₃— Pro- C₁₄H₂₆N₂O 50

—CH₂—CH₂— Pro- C₁₄H₂₄N₂O 51 (CH₃)₂CH— CH₃— CH₃— (CH₃)₂CHSO₂— C₉H₂₁N₂OS52 (CH₃)₂CH— CH₃— CH₃—

C₁₃H₁₈ClNO 53 (CH₃)₂CH— CH₃— CH₃—

C₁₂H₂₄N₂O₂ 54 (CH₃)₂CH— CH₃— CH₃—

C₁₂H₁₉NOS 55 (CH₃)₂CH— CH₃— CH₃—

C₁₆H₂₂N₂O 56

—CH₂—CH₂—

C₁₅H₂₀N₂O 57

CH₃— CH₃— (CH₃)₂CH— C₁₆H₂₆ClN₂O

When R₂, R₃ and R₄ each represents alkyl or alkylene, and R₁ representsα-hydroxyalkyl, α-hydroxycycloalkyl or nitrate thereof, the preferredcompound of formula I substituted with an alcohol or ester thereof isshown in Table 3.

TABLE 3 the preferred compound represented by formula I wherein thesubstituents comprise an alcohol or ester thereof compound R₁ R₂ R₃ R₄formula 58

CH₃— CH₃— (CH₃)₂CH— C₉H₂₁NO 59

CH₃— CH₃—

C₁₂H₂₇NO 60

CH₃— CH₃— (CH₃)₂CH— C₁₂H₂₅NO 61

—(CH₂)₅— (CH₃)₂CH— C₁₅H₂₉NO 62

CH₃— CH₃— (CH₃)₂CH— C₁₁H₂₃NO 63

—(CH₂)₄— (CH₃)₂CH— C₁₃H₂₅NO 64

CH₃— CH₃— (CH₃)₂CH— C₉H₂₀N₂O₃ 65

CH₃— CH₃— (CH₃)₂CH— C₁₂H₂₄N₂O₃ 66

CH₃— CH₃— (CH₃)₂CH— C₁₁H₂₂N₂O₃ 67

—(CH₂)₅— (CH₃)₂CH— C₁₅H₂₈N₂O₃ 68

—(CH₂)₄— (CH₃)₂CH— C₁₃H₂₄N₂O₃ 69

CH₃— CH₃— (CH₃)₂CH— C₁₅H₂₄N₂O₂ 70

CH₃— CH₃—

C₁₈H₃₀N₂O₂ 71

—(CH₂)₅—

C₂₄H₃₈N₂O₂

When R₁, R₂ and R₃ each represents alkyl or cycloalkyl, and R₄represents imidazolinyl, thiazolinyl or substituted imidazolinyl, thecompound of formula I of which R₄ is heterocyclo is shown in Table 4

TABLE 4 The compound of formula I, wherein R₄ is heterocyclo. compoundR₁ R₂ R₃ R₄ formula 72 (CH₃)₂CH— CH₃— CH₃—

C₉H₁₉N₃ 73 (CH₃)₂CH— CH₃— CH₃—

C₉H₁₈N₂O 74 (CH₃)₂CH— CH₃— CH₃—

C₉H₁₈N₂S 75

CH₃— CH₃—

C₁₂H₂₃N₃ 76

CH₃— CH₃—

C₁₁H₂₁N₃ 77

CH₃— CH₃—

C₁₂H₂₂N₂S 78

CH₃— CH₃—

C₁₁H₂₀N₂S 79

CH₃— CH₃—

C₁₂H₂₂N₂O 80

CH₃— CH₃—

C₁₁H₂₀N₂O 81 (CH₃)₂CH— CH₃— CH₃—

C₁₅H₂₂N₄O 82 (CH₃)₂CH— CH₃— CH₃—

C₂₁H₃₀N₄O₂ 83 (CH₃)₂CH— CH₃— CH₃—

C₁₂H₂₅N₃ 84 (CH₃)₂CH— CH₃— CH₃—

C₁₀H₂₁N₃

Furthermore, R₄ may form cyclic compound with R₁, R₂ and R₃, such ascyclic analogues of the compounds shown in Table 1, 2 and 3. Thepreferred are 2,2,3,5-tetramethyltetrahydropyrrole,2,2,3,6-tetramethylpiperidine, and 2,2,3,7-tetramethylaxacycloheptane,

Moreover, the compound represented by formula I_(a) can form an amide oran ester derivative with an organic acid, wherein said organic acid ispreferably nicotinic acid, cinnamic acid, maleic acid,2,4,5-trichlorophenoxyacetic acid and 3-hydroxy-3-methylglutaric acid.

According to this invention, one general procedure for preparing thecompound represented by formula I_(a) is as follows: a suitable primaryamine R′₁R′₂R′₃CNH₂ and R′₄X are heated and/or pressurized in a reactorin absence of solvent or in the presence of an organic solvent, whereinthe organic solvent may be carbohydron, aromatic solvent or alcohol suchas cyclohexane, pentane, hexane, heptane, octane, nonane, decane,duodecane, benzene, toluene, xylene, nitrobenzene, glycol, propanediol,propanetriol, etc.; In the case of an organic solvent used, a catalystmay or may not present the catalyst may be organic or inorganic base oralcohol such as potassium hydroxide, sodium hydroxide, pyridine, glycol,propanediol, propanetriol, low molecular weight polyglycol, etc.; thereaction temperature range is 50 to 400 degree of centigrade, preferably110 to 250 degree of centigrade; The reaction pressure depends on thesolvent used and the temperature, usually ranging from 0.1 to 20 millionpascal, preferably from 0.5 to 15 million pascal. The reactiontemperature can also be obtained by filling of nitrogen, helium, andargon, etc. The product is isolated and purified by generalrecrystalization and/or chromatography. Suitable pharmacentical saltsmay be produced by reacting the compound represented by formula Ia withan inorganic acid or organic acid, if deired.

According to the invention, the second procedure for preparing thecompound represented by formula Ia is as follows: a primary amineR′₁R′₂R′₃CNH₂, an aldehyde or ketone of R′₄ and a catalyst are heated to30-300° C. and/or pressurized to 0.1-20 MPa for hydrogenation in absenceof or in the presence of an organic solvent, wherein R₁′, R₂′, R₃′ andR₄′ are defined as above, the catalyst may be palladium carbon, Raneynickel, platium oxide and nickel-copper, and said organic solvent may beexcess amount of aldehyde or keltone of R′₄, toluene, xylene,1,2-dichloroethane, 1,4-dioxane, dimethoxyethane, methanol and ethanol.

In the aforesaid procedure, the primary amine is prepared throughhydrolysis of hydrocarbylurea R′₁R′₂R′₃CNHCONH₂, which is produced byreacting urea with alkene or alcohol of R₁′ R₂′ R₃′C or the mixture ofboth and concentrated sulfuric acid in the presence of an organic acidat 20-200° C., wherein the organic acid is acetic acid, trifluoroaceticacid or methanesulfonic acid.

In the aforesaid procedures, when the compound represented by formula Iis a secondary alkylamine, a secondary amide or a secondary sulfonamide,it can be prepared by a known method in the art, see M. S. Dunn, B. M.Smart., Org. Synth., 1963, Coll. Vol. IV: 55; Houben-Weyl., XI/2: 482;J. B. Hendrickson, R. Bergeron, Tetrahedron Lett., 1973: 3839. It canalso be produced by forming an imine or Schiff base followed byreduction or catalytic hydrogenation, see D. M. Balcom, C. R. Noller,Org. Synth., 1963, Coll. Vol. IV: 603; Cesare Ferri, “Reaktionen derorganischen Synthese”, Stuttgart, 1978, p. 85. There are special methodsfor preparing a secondary amine, for example, the substituted secondaryamine can be produced by reacting a Schiff base or an imine with aGrignard agent, see Klusener P. A. A, Tipl and Brandsma, Tetrahedron,1991, 2041; Klusener P. A. A, J. Chem. Soc., Chem. Commun., 1985, 1677.

When the secondary amine represented by formula I has a α-substituent ofhydroxy or amino, it can be produced by reacting an epoxy compound or anaziridine derivative with a primary amine, see O. C. Dermer, G. E. Ham.“Ethylenimine and other Aziridines”, Academic Press, New York, 1969; L.B. Clapp, J. Amer. Chem. Soc., 1948, 70: 184.

When R₄ of formula I represents an amino acid residue or a small peptideconsisting thereof, the compound herein can be produced by a knownmethod termed as protection-condensation-deprotection, see Ming Zhao,Chin. J. Med. Chem., 1995, 5(2): 91; Gu Mingdi, Peng Shipi, Yu Xuemin,J. Chin. Pharm. Sci., 1993, 2(2): 102.

When R₄ of formula I represents hydrogen, the compound (i.e. a primaryamine) can be prepared by hydrolysis of a corresponding amide producedthrough a Ritter reaction, see U.S. Pat. No. 1972, 3673249. Thisinvention further provides, a method for preparation of a primary amine,which comprises reacting urea with a corresponding alkene or alcohol ora mixture of both and concentrated sulfuric acid in the presence of anorganic acid at a temperature ranging from 20 to 200 degree ofcentigrade, wherein the organic acid may be acetic acid, trifluoroaceticacid or methanesulfonic acid, followed by hydrolysis of thehydrocarbylurea with a catalyst, such as an acid, a base etc.

According to the invention, the compound represented by formula I orI_(a) can exist in the form of stereoisomers. The chiral center of thecompound represented by formula I may be in configuration of S- or R-.The invention includes all possible stereoisomers such as enantiomers ordiastereomers, and the mixture of two or more stereoisomers such as themixture of enantiomers and/or diastereomers in any desired proportion.Therefore, the invention relates to enantiomers such as purelevo-enantiomer or dextro-enantiomer, and the mixture of both forms inany proportion or racemes. If there are cis-/trans-isomers, theinvention also relates to the cis-form and trans-form and the mixture ofboth forms. If needed, the desired pure stereoisomer can be prepared bygeneral resolution of the mixture or: by, stereospecific synthesis. Ifthere is a movable hydrogen, the invention also relates to tautomers.

According to the invention, the compound represented by formula I andits stereoisomers show excellent effects in prophylaxis or treatment ofcardiovascular diseases such as hypertension, arrhythm, anginadiaphragmatic, congestive heart failure, and myocardial infarction,diabetes, bronchial and urinary smooth muscle spasm. Therefore, they canbe used as drugs for prophylaxis or treatment of cardiovascular diseasesof animals, preferably of mammalian, especially of man.

Therefore, the invention also relates to pharmaceutical compositionscontaining as an active component an effective amount of at least onecompoumd represented by formula I or I_(a), or its pharmaceutical saltsand/or its stereoisomers, and conventional excipients or adjuvants.Usually, the pharmaceutical composition, of this invention contains 0.1to 90 percent weight of the compound of formula I or Ia, or itsphysiologically acceptable salts. The pharmaceutical composition can beprepared according to the known method of this field. For use asmedicaments, the compound of formula I or I_(a) and/or its stereoisomermay be fomulated into proper forms or dosages for administration to manby combination with one or more solid or liquid excipient and/oradjuvant, if needed.

The compound of formula I or I_(a) in this invention, or itspharmaceutical composition can be administered in a single dosage formthrough enteral or parenteral routes, such as oral, intramuscular,subcutaneous, nasal, oral mucosal, cutaneous, peritoneal or rectaladministration. Such medicaments can be formualted into tablets,capsules, drops, aerosols, pills, powders, solutions, suspensions,emulsions, granules, liposomes, patches, buccal tablets, suppositories,lyophilized powders for injection, and so on. It can be formulated intoordinary preparation, delayed release preparation, controlled releasepreparation, and various microparticle delivery system. In order toformulate a single dose of medicaments into tablets, the well-knowncarriers can be extensively used. Examples of carriers are as follows:diluents and absorbents such as starch, dextrine, calcium sulfate,lactose, mannitol, sucrose, sodium chloride, glucose, urea, calciumcarbonate, kaolin, avicel, aluminium silicate, etc.; humectans andadherents such as water, glycerol, polyethylene glycol, ethanol,propanol, starch paste, dextrine, syrup, honey, glucose solution, acaciapaste, gelatin paste, sodium carboxymethyl cellulose, lac, methylcellulose, potassiun phosphate, polyvinyl pyrrolidone, etc.;disintegrating agent such as droughty starch, alginate, agar powder,laminaran, sodium hydrocarbonate, citric acid, calcium carbonate,polyoxyethylenesorbol fatty acidic ester, sodium dodecyl sulphate,methyl cellulose, ethyl cellulose, etc.; disintegratation inhibitorssuch as sucrose, glycerol tristearate, cocoa oil, hydrgenated oil, etc.;absorbent accerelants such as quarternary ammonium salts, sodium laurylsulfate, etc.; lubricants such as talc, silica, cornstarch, stearate,boric acid, liquid wax, polyglycol, etc. The tablets can be furtherformulated into coating tablets such as sugar coating, film coating,enteral dissolution coating, or double-layered tablets and multi-layeredtablets. In order to formulate a single dose of medicaments into pills,the well-known carriers can be extensively used. Examples of suchcarriers are as follows: diluents and absorbents such as glucose,lactose, starch, cocoa fat, hydrogenated vegetable oil, polyvinylpyrrolidone, gelucire, kaolin, talc etc.; adherents such as acacia,bassora gum, gelatin, ethanol, honey, liquid sugar, rice paste or flourpaste, etc.; disintegrating agents such as agar powder, droughty starch,alginate, sodium dodecyl sulphate, methyl cellulose, ethyl cellulose,etc. In order to formulate a single dose of medicaments intosuppositories, the well-known carriers can be extensively used. Examplesof such carriers are as follows: polyglycol, lecithin, cocoa fat, higheralcohol, ester of higher alcohol, gelatin, semi-synthesized glyceride,etc. In order to formulate a single dose of medicaments into capsules,the active compound of formula I or I_(a) or its stereoisomers can beadmixtured with the aforesaid carriers, and the resulting mixture cansbe capsuled into hard gelatin capsules or soft capsules. The activecompound of formula I or Ia or its stereoisomers can also be formulatedinto microcapsules. Microcapsules can be suspended in aqueous solutionand formulated into suspensions, or encapsuled in hard capsules, orformulated into injectable preparations. In order to produce injectablepreparations such as solutions, emulsions, lyophilized powder forinjection and suspensions, all the diluents commonly used in the art canbe used, for examples, water, ethanol, polyglycol, 1,3-propanediol,ethoxylated isostearol, polyoxidized isostearol, polyoxyethylene sorbolfatty acidic ester, etc. In addition, in order to prepare isosmoticsolutions, the injectable preparations can be appended proper amount ofsodium chloride, glucose or glycerol; furthermore, they can also beadded with conventional cosolvent, buffers, pH modulator, etc.

Moreover, the medicaments can also be appended colorants, antiseptics,flavors, condiments, sweets, or others, if needed.

The administration dosage of the compound of fomula I or Ia in thisinvention, its pharmaceutical salts or its stereoisomers depends on manyfactors, including the property and severity of the diseases to beprevented or to be treated, sex, age, body weight and individualresponsiveness of the animal or patient, the specific compound used,administration routes, and administration times, etc. The aforesaiddosage can be a single dosage form or multiple dosage forms such as two,three or four dosage forms.

EXAMPLES

The following examples illustrate the present invention morespecifically, but that does not mean any limitation to the invention.

Example 1

Production of N-(1-methylethyl)-2,3-dimethyl-2-butylamine (Compound 1):Method 1. The solution of 7.6 g (0.0745 mole) 2,3-dimethyl-2-butanol in3.24 mL glacial acetic acid was cooled and maintained at −5 to −8 degreeof centigrade (° C.), then was added 7.3 g (0.49 mole) of powderedpotassium cyanide in several times under stirring. 32.4 mL concentratedsulfuric acid was added dropwise while keeping the temperatue below 20 °C., after which, the reaction mixture was stirred for 3.5 hours below20° C. and another 6 hours at room temperature, then stood overnight.After poured into ice colded water, the mixture was adjusted to pH10with 20% aqueous sodium hydroxide solution, and extracted with ether(×4). The extract was dried over anhydrous sodium sulfate. Afterfiltration on the next day, the dessicator was removed, and the filtratewas evaporated off the ether, then distilled in vacuum to give 8.8 g(yield 91.6%) N-[2-(2,3-dimethylbutyl)]-fomide; bp 105-108° C./5 mmHg.

To the mixture of 7.7 g (0.0597 mole) N-[2-(2,3-dimethylbutyl)]-formide,6.2 mL ethanol and 51.6 mL wate, 17.4 mL concentrated hydrochloric acidwas added. The reaction mixture was refluxed for 4 hours in the oilbath, then distilled off ethanol in vacuum. The residue was adjusted toabove pH12 with 40% aqueous sodium hydroxide solution, and extractedwith ether. The extract was dried over anhydrous potassiun carbonate.After recovering the ether, The residue was distilled at atmosphere togive 3.75 g (yield 62.2%) 2,3-dimethyl-2-butylamine, bp 97-104° C.

The mixture of 10.6 g (0.15 mole) 2,3-dimethyl-2-butylamine, 6.45 g(0.0524 mole) 2-bromopropane, 3.0 mL glycol and 22.0 mL toluene wasadded into an autoclave, and heated with stirring for 17 hours attemperature of 170° C., after which, the organic layer was separated andextracted with 6N hydrochloric acid (15 mL×4). The extract was combinedand washed once with toluene, then adjusted to pH 12-13 with 4% aqueoussodium hydroxide in the ice bath. The mixture was extracted with etherand then dried over anhydrous potassium carbonate. After recovering theether, The filtrate was distilled to yield the fraction of bp 135-145°C. (yield 68.8%). The hydrochloride's Mp is 228-230° C. (i-PrOH-Et₂O).Elemental analysis for C₉H₂₂ClN(%): Calculated C, 60.14; H, 12.34; N,7.79, Cl 19.73. Found C, 60.14; H, 12.48; N, 7.31, Cl 19.67. ¹H-NMR(D₂O,ppm) 0.98(d, J=6.75H, 6H), 1.33(s, 6H), 1.37(d, J=6.46, 6H), 2.10(m,1H), 3.70(m, 1H). MS(m/z) 143 (M+), 100(B).

Method 2. To the mixture of 288 mL glacial acetic acid, 412 g (6.86mole) urea and 288 g (3.43 mole) 2,3-dimethyl-2-butene, the solution of412 mL concentrated sulfuric acid and 412 mL of glacial acetic acid wasadded dropwise under stirring, while maintaining the reactiontemperature at the range of 45° C. to 50° C., then stirred for 5 hoursat the temperature of 50-55° C. The mixture stood overnight. Next day,the mixture was reacted for another 7 hours at the temperature of 50-55°C., then poured into the solution of 1200 g (30 mole) sodium hydroxidein 8 L glacial water. The resulting solid was filtered, washed withwater (200 mL×5) and dried to give 404 g (yield 81.8%)N-(2,3-dimethyl-2-butyl)urea as white solid, mp 175-176° C. Elementalanalysis for C₇H₁₆N₂O(%): Calculated C, 58.30; H, 11.18; N, 19.42. FoundC, 58.70; H, 11.54; N, 19.25. ¹H-NMR(CDCl₃, ppm) 0.88-0.91(d, 6H,2×CH₃), 1.26(s, 6H, 2×CH₃), 2.20-2.26(m, 1H, CH), 4,45(br, 2H), 4.65(br,1H). MS(m/z) 145.0, 144.0(M⁺), 143.0, 129.1, 101.0, 86.1, 69.1, 58.0(B).

To the mixture of 196 g (1.36 mole) N-(2,3-dimethyl-2-butyl)urea and 392mL glycol or tri-(ethanol)amine, a solution of 118 g (2.95 mole) sodiumhydroxide in 118 mL water was added. The reaction mixture was heated for8 hours in an oil bath at temperature of 120° C., then distilled atatmosphere to collect the fraction of bp 95-102° C. To the fraction, 75g anhydrous potassium carbonate and. 40 g sodium hydroxide were added.The resulting mixture was distilled to give 88.5 g (yield 64.3%)2,3-dimethyl-2-butylamine as colorless liquid, bp 99-101° C.¹H-NMR(CDCl₃, ppm) 0.88-0.91(d, 6H, 2×CH₃), 1.04 (s, 6H, 2×CH₃), 1.53(m,1H, CH).

To a 50.0 ml autoclave, 10.6 g (0.15 mole) 2,3-dimethyl-2-butylamine,6.45 g (0.0524 mol) 2-bromopropane, 3.0 ml glycol and 22.0 ml toluenewere added, and heated with stirring for 17 hours at 170° C., afterwhich the organic layer was seperated and extracted with 6N hydrochloricacid (15 ml×4). The extract was combined and washed once with toluene,then adjusted to pH 12-13 with 4% aqueous sodium hydroxide in the icebath. The mixture was extracted with ether and then dried over anhydrouspotassium carbonate the ether was recovered, and distilled to give thefraction of bp 135-145° C. (yield 68.8%). mp of the hydrochloride is228-230° C., (i-PrOH: Et₂O). Elemental analysis for C₉H₂₂ClN(%):Calculated C, 60.14; H, 12.34; N, 7.79; Cl, 19.73. Found C, 60.14; H,12.48; N, 7.31; Cl 19.67. ¹H-NMR(D₂O, ppm) 0.98(d, J=6.75H, 6H), 1.33(s,6H), 1.37(d, J=6.46, 6H), 2.10(m, 1H), 3.70(m, 1H). MS(m/z) 143 (M⁺),100(B).

Method 3. a solution of 0.10 mole enamine (prepared from thecondensation of methyl iso-propyl ketone and iso-propylamine) in 20 mLhexane was filled with N₂ and added dropwise to a solution containing0.10 mole lithium methide with stirring in ice bath. After the reactionis complete, the mixture was poured into 500 g glacial water, andstirred. The aqueous layer was extracted with ether (×2). The resultingorganic layer was concentrated. 3N hydrochloric acid was added toacified the organic layer to pH<1. The mixture was kept for ten minutesand adjusted to pH>11 with 10% aqueous sodium hydroxide, then extractedwith ether (×3). The extract was dried over anhydrous potassiumcarbonate and filtered. The filtrate was distilled at atmosphere to givea fraction of bp 140-145° C. with a yield of 80%.

Example 2

Preparation of N-propyl-2,3-dimethyl-2-butylamine (compound 5)

To a solution of 8.25 g (0.15 mole) propionitrile in 25 mL glacialacetic acid, 15 g concentrated sulfuric acid was added dropwise whilecontrolling the reaction temperature at about 38° C., then 5.2 g (0.051mole) of 2,3-dimethyl-2-butanol was added dropwise at the temperaturebelow 40° C. with stirring. The mixture was stirred overnight whilemaintaining the temperature, then poured into glacial water, basifiedwith 40% sodium hydroxide solution and extracted with ether. The etherextract was combined, washed once with water, and dried over anhydrousmagnesium sulfate. After recovering the ether, 6.2 g light yellow liquidwas obtained and solved in 80 mL anhydrous ether. The resulting solutionwas added dropwise to a suspension of 3.04 g (0.08 mol) lithiumaluminium hydride in 80 mL anhydrous ether. The mixture was refluxed for10 hours, then cooled. To the mixture, proper amount of 40% aqueoussodium hydroxide was added dropwise and the upper layer of ether wascarefully poured out. The lower layer of solid was then washed withether (×3). The resulting washing and extract ether were combined, driedover anhydrous potassium carbonate and filtered. To the filtrate,HCl-Et₂O was added under cooling until the solution is acidic. The solidwas collected by filtering and recrystallized three times fromiso-propanol and acetone to give a white lamellar crystal 3.33 g (yield46.33%), mp 183-185° C. Elemental analysis for C₉H₂₂NCI (%): CalculatedC, 10.15; H, 12.34; N, 7.79. Found C, 60.20; H, 13.80; N, 7.85.¹H-NMR(D₂O, ppm) 0.98(d, 6H), 1.00(t, 3H), 1.24(s, 6H), 1.63(m, 2H),2.05(m, 1H), 2.98(t, 2H). MS(m/z) 143(M⁺).

Example 3

Preparation of N-(1-methylpropyl)-2,3-dimethyl-2-butylamine (compound13)

Similar treatment of 2,3-dimethyl-2-butylamine with bromoisobutane asexample 1 gave compound 13 with a yield of 17.1%. The melting point (mp)of the hydrochloride is 203-204° C. Element analysis for C₁₀H₁₄NCl (%):Calculated C,61.99; H,12.49; N7.23. found C,62.17; H,13.18; N,7.27. MS(m/z) 157(M⁺); ¹H-NMR(D₂O, ppm) 0.90 (d, 6H), 1.18(t, 3H), 1.26(d, 3H),1.28-3.43(m, 19H).

Example 4

Preparation of N-cyclopropylmethyl-2,3-dimethyl-2-butylamine (compound15)

Similar treatment of 2,3-dimethyl-2-butylamine withbromomethylcyclopropane as example 1 gave compound 15 with a yield of27.6%. The melting point (mp) of hydrochloride is 176-178° C. Elementalanalysis for C₁₀H₁₁NCl (%): Calculated C, 62.64; H, 11.57; N, 7.31.Found C, 62.69; H, 11.82; N, 7.01. ¹H-NMR(D₂O, ppm) 0.95(d, 6H),1.30-3.10(m, 14H), 5.20(m, 1H). MS(m/z) 155(M⁺), 112(M⁺-43).

Example 5

Preparation of N-allyl-2,3-dimethyl-2-butylamine (compound 25)

Similar treatment of 2,3-dimethyl-2-butylamine with allylbromide asexample 1 gave compound 25 with a yield of 79.3%. The melting point (mp)of the hydrochloride is 173-175° C. Elemental analysis for C₉H₂₀NCl (%):Calculated C, 60.80; H, 11.34; N, 7.88. Found C, 60.68; H, 11.43; N,7.94. ¹H-NMR(D₂O) 0.98(d, 6H), 1.31(s, 6H), 2.20(m, 1H), 3.66(d, 2H),5.87(m, 2H), 5.95(m, 1H). MS(m/z) 141(M⁺).

Example 6

Preparation ofN-{2-[di-(1-methylethyl)amino]ethyl}-2,3-dimethyl-2-butylamine(compound, 27)

Similar treatment of 2,3-dimethyl-2-butylamine with2-(diisopropylamine)-ethylbromide as example 1 gave compound 27 with ayield of 31.8%. The melting point (mp) of the hydrochloride is 176-178°C. Elemental analysis for C₁₄H₃₄N₂Cl₂ (%): Calculated C, 55.80; H,11.37; N, 9.30.; Found C, 55.90; H, 11.68; N, 9.21. ¹H-NMR(D₂O, ppm)1.01(d, 6H), 1.38(s, 6H), 1.40(d, 12H), 2.04(m, 1H), 3.39-3.83(m, 6H).MS(m/z) 229(M⁺).

Example 7

preparation of N-butyl-2,3-dimehyl-2-butylamine (compound 6).

According to the method of example 2, the Ritter reaction ofbutyronitrile and 2,3-dimethyl-2-butanol produced an amide intermediate,which was then reduced by lithium aluminium hydride to give compound 6with a yield of 26.1%. The melting point (mp) of the hydrochloride is140-142° C. Elemental analysis for C₁₀H₂₄NCl (%): Calculated C,61.99;H,12.49; N,7.23. Found C, 62.06; H,12.73; N,5.90. MS(m/z) 157(M+).¹H-NMR(D₂O, ppm) 0.98(d, 6H), 1.42(s, 6H), 1.45(t, 3H), 1.65(m 6H),2.31(m, 1H).

Example 8

Preparation of N-propyl-α-methyl-phenylpropylamine (compound 21)

Similar treatment of propionitrile with 2-phenyl-2-butanol as example 2gave compound 21. The melting point (mp) of the hydrochloride is159-161° C. Elemental analysis for C₁₃H₂₂NCI (%): Calculated C, 68.55;H, 9.73; N, 6.15. Found C, 68.59; H, 10.22; N, 5.86. ¹H-NMR(D₂O, ppm)0.83(m, 6H, 2CH₃), 1.58(m, 2H, CH₂), 1.78(s, 3H, CH₃), 2.05(m, 1H, CH),2.29(m, 1H, CH), 2.53(m, 1H, CH), 2.85(m, 1H, CH), 7.54(m, 5H, Ar—H).MS(m/z) 192(M⁺), 133(M⁺-C₃H₈N).

Example 9

Preparation of N-propyl-α,β-dimethyl-phenylpropylamine (compound 19)

Similar treatment of propionitrile with 2-phenyl-3-methyl-2-butanol asexample 2 gave compound 19. The melting point (mp) of the hydrochlorideis 190-192° C. Elemental analysis for C₁₄H₂₄NCl (%): Calculated C,69.54; H, 10.00; N 5.79. Found C, 69.43; H, 10.40; N, 5.41. ¹H—NMR(D₂O,ppm) 0.98(t, 3H, CH₃), 1.28(s, 3H, CH₃), 1.39(t, 6H, 2CH₃), 1.63(m, 2H,CH₂), 3.98(m, 1H, CH), 3.12-3.28(m, 2H, CH₂), 7.43(m, 5H, Ar—H). MS(m/z)206(M⁺), 147(M⁺-C₃H₈N).

Example 10

Preparation of N-(3-pyridyl)methyl-2,3-dimethyl-2-butylamine (compound39)

Similar treatment of 3-cyanopyridine with 2,3-dimethyl-2-butene asexample 2 gave compound 39. The melting point (mp) of the hydrochlorideis 166-168° C. , for C₁₂H₂₉ClN₂O (%): Calculated C, 59.36; H, 7.89; N,11.54. Found C, 59.33; H, 7.98; N, 11.45. ¹H—NMR(D₂O, ppm) 0.92(d, 6H,2CH₃), 1.42(s, 6H, 2CH₃), 2.42(m, 1H, CH), 8.13(q, 1H, ArH), 8.86(m, 2H,ArH), 9.08(s, 1H, ArH). MS(m/z) 207(M⁺), 106(M⁺-C₆H₁₄N).

Example 11

Preparation of N-valyl-2,3-dimethyl-2-butylamine (compound 37)

To a solution of 0.434 g (2 mmole) Boc-Val in 2.5 mL anhydroustetrahydrofuran (THF), 0.200 g (2 mmole) 2,3-dimethyl-2-butylamine and0.135 g (1 mmole) HOBt were added, while stirring untill the solid wascompletely dissolved. The mixture was cooled in an ice bath, and asolution of 0.412 g (2 mmol) DCC in 2.5 mL THF was added dropwise. Themixture was stirred for 4 h, then stood overnight and distilled off thesolvent in vacuum to give a white solid. The solid was completelydissolved in 7.5 mL ethyl acetate, washed twice with saturated aqueoussodium bicarbonate, twice with saturated aqueous citric acid solutionand twice with water in turn, then dried over anhydrous magnesiumsulfate and filtered. The filtrate was washed twice with 7 ml ethylacetate and 5 mL HCl-Et₂O was added. After shaking, The mixture wasstood for 5 hours at room temperature druing which shaking four times,then distilled off ether at room temperature, and distilled off ethylacetate in vacuum in warm water bath to give a white laminar solid. 10ml anhydious ether was added and stirred. The mixture was distilled invacuum to remove ether. 0.324 g solid was obtained. The solid wasrecrystallized from anhydrous ethanol-ethyl acetate to give 0.165 g(yield 35%) product. The melting point of the hydrochloride is 240-241°C. Elemental analysis for C₁₁H₂₅ClN₂O (%): Calculated C, 55.80; H,10.64; N, 11.83. Found C. 55.85; H, 10.71; N, 11.63. MS(m/z) 201.0(M⁺).

Example 12

Preparation of N-tryptophanyl-2,3-dimethyl-2-butylamine (compound 40)

Similar treatment of Trp-Boc with 2,3-dimethyl-2-butylamine and DCC asexample 11 gave compound 40 with a yield of 17.5%. The melting point(mp) of the hydrochloride is 135-137° C.(EtOH-EtAc-Et₂O). MS(m/z)287(M⁺).

Example 13

Preparation of N-(N-nitroarginyl)-2,3-dimethyl-2-butylamine (compound44)

Similar treatment of Boc-Arg(NO₂) with 2,3-dimethyl-2-butylamine and DCCas example 11 gave compound 44 with a yield of 36.4%. The melting point(mp) of the hydrochloride is 175° C. (dec.)(EtOH-EtAc). MS(m/z):302(M⁺).

Example 14

Preparation of N-phenylalanyl-2,3-dimethyl-2-butylamine (compound 43)

Similar treatment of Boc-Pha with 2,3-dimethyl-2-butylamine and DCC asexample 11 gave compound 43 with a yield of 21.8%. The melting point(mp) of the hydrochloride is 232-233° C. (EtOH-Et₂O). MS(m/z) 248(M⁺).

Example 15

Preparation of N-leucyl-2,3-dimethyl-2-butylamine (compound 42)

Similar treatment of Boc-Leu with 2,3-dimethyl-2-butylamine and DCC asexample 11 gave compound 42. The melting point (mp) of the hydrochlorideis 250-252° C.(EtOH-Et₂O). MS(m/z) 214(M⁺).

Example 16

Preparation of N-isoleucyl-2,3-dimethyl-2-butylamine (compound 41)

Similar treatment of Boc-Ile with 2,3-dimethyl-2-butylamine and DCC asexample 11 gave compound 41. The melting point (mp) of the hydrochlorideis 246-248° C. (EtOH-Et₂O). MS(m/z) 214(M⁺).

Example 17

Preparation of N-tosyl-2,3-dimethyl-2-butylamine (compound 38)

To a solution of 1.2 g (0.012 mole) 2,3-dimethyl-2-butylamine in 20 mLpyridine, a solution of 1.9 g (0.010 mole) tosylchloride in 20 mLpyridine was added dropwise in a glacial water bath, stirred for 3 hoursin that bath and 1 hour at room temperature, then heated for 2 hours ina bath at temperature of 95-100° C. The solvent was distilled off invacuum. Toluene was added to the residue, then distilled off the solventin vacuum. The residue was dissolved in water and extracted with toluene(×4). The toluene extract was washed with water once, dried overanhydrous magnesium sulfate and filtered. The filtrate was distilled offthe solvent. The residue was recrystallized from isopropanol to give acolorless columnar crystal 1.1 g, mp 80-89° C., recrystallized fromisopropanol once again to give a white crystal 0.8 g, mp 88-89° C.Elemental analysis for C₁₃H₂₁NO₂S (%): Calculated C, 61.14; H, 8.29; N,5.48. Found C, 61.11;, H, 8.37;, N, 5.55. ¹H-NMR(CDCl₃; ppm) 0.91(d,J=6.8 Hz, 6H, 2CH₃), 1.17(s, 6H, 2CH₃), 1.82(M, 1H, CH), 2.47(s, 3H,CH₃), 7.32(d,J=8.0, 2H,2Ar—H), 7.82(d, J=8.0, 2H, 2Ar—H′). MS(M/z) 255(M⁺), 172(B).

Example 18

Preparation of N-(1-methylethyl)-2,3-dimethyl-3-hydroxy-2-butylamine(compound 58)

To an autoclave, 41.8 g (0.418 mole) 2,3-dimethyl-2,3-epoxyethane, 20.0g (0.33 mole) 2-propylamine and 50 mL toluene were added. The mixturewas stirred for 48 h at 170° C., then cooled to room temperature andextracted with 6N aqueous hydrochloric acid (35 mL×3). The acid extractwas combined and washed with proper amount of toluene, then adjusted topH 12 with 40% aqueous sodium hydroxide and extraced with ether (50mL×3). The ether extract was combined, dried over anhydrous potassiumcarbonate and filtered. The filtrate was distilled off ether, thendistilled in vacuum to give2-(N-2-methylethyl)-3-hydroxy-2,3-dimethylbutylamine, bp 60-65/10 mmHg.The melting point of the hydrochloride is 156-158° C. (EtOH-Et₂O).Elemental analysis for C₉H₂₂ClNO (%): ; C, 55.23; H, 11.33; N, 7.16.Found C, 55.23; H, 11.65; N, 6.95. ¹H-NMR(CDCl₃, ppm) 1.33(s, 6H, 2CH₃),1.41(d, 6H, 2CH₃), 1.42(s, 6H, 2CH₃), 3.81(m, 1H, CH). MS(m/z) 160 (M+).

Example 19

Preparation of N-(1-methylethyl)-2,3-dimethyl-2-butylamine tosylate

Anhydrous tosylic acid: Tosylic acid hydrate was heated to distill offcrystal water at the temperature of 110° C. until no water vapored, thencooled in a desiccator for use in the next step.

0.60 g (3.5 mmole) anhydrous tosylic acid was dissolved in possibly aslittle as ethanol. Then a solution of 0.55 g (0.38 mmole)N-(1-methylethyl)-2,3-dimethyl-2-butylamine in 10 mL anhydrous ether wasadded dropwise with stirring. The mixture was stood overnight, and thendistilled off the solvent. The residue was washed thoroughly withanhydrous ethanol to give a colorless solid 1.07 g, mp 119-120° C.¹H-NMR(D₂O, ppm) 0.96(d, 6H, 2CH₃), 1.303(s, 6H, 2CH₃), 1.36(d, 6H,2CH₃), 2.02-2.15(m, 1H, C(H), 2.401(s, 3H, CH₃), 3.62-3.73(m, 1H, CH),7.38(d,2H, 2Ar—H), 7.70(d,2H, 2Ar—H).

Example 20

Preparation of N-(1-methylethyl)-2,3-dimethyl-2-butylamine•hydrochloride

To a solution of 100.0 g N-(1-methylethyl)-2,3-dimethyl-2-butylamine in200 mL ethanol, 100 mL hydrochloric acid was added with shaking andcooling in an glacial water bath. The solvent was distilled off to dryin vacuum. The residue was dissolve in ethanol, then distilled off todry in vacuum and crystallized from 1:1 i-PrOH-c-Hex-H to give a solid130.5 g (95.5%), mp 228-230° C.(i-PrOH:Et₂O). Elemental analysis forC₉H₂₂ClN(%): Calculated C, 60.14; H, 12.34; N, 7.79; Cl, 19.73. Found C,60.14; H, 12.48; N, 7.31; Cl, 19.67. ¹H-NMR (D₂O, ppm) 0.98(d, J=6.75H,6H), 1.33(s, 6H), 1.37(d, J=6.46, 6H), 2.10(m, 1H), 3.70(m, 1H). MS(m/z)143(M⁺), 100(B).

Example 21

Preparation ofN-(1-methylethyl)-N-(2,4,5-trichlorophenoxy-acetyl)-2,3-dimethyl-2-butylamine

The mixture of 51.3 g 2,4,5-trichlorophenoxyacetic acid and 18 mLthionyl chloride was refluxed with: stirring for 2.5 hours. Then smallquantity of dry benzene was added and distilled off excess thionylchloride and benzene in vacuum. The residue was cooled and a white solidcrystallized out, which is 2,4,5 trichlorophenoxyacetyl chloride.

To the mixture of 1.81 gN-(1-methylethyl)-2,3-dimethyl-2-butylamine•hydrochloride, 3.30 gtriethylamine, catalytic amount of 4-dimethylaminopyridine and 50 mLtoluene, a solution of 5.50 g 2,4,5-trichlorophenoxyacetyl chloride in20 mL toluene was added dropwise with stirring. After addition, themixture was heated for 14 hours in an oil bath at temperature of 80° C.,then cooled to ambient temperature and filtered. The resulting solid waswashed with toluene. The filtrate and the washing toluene were combined,washed with 50 mL water, 1N NaOH (50 mL×2), 50 mL water, 1N HCl (50mL×2) and 50 mL water in turn, and dried over anhydrous sodium sulfateto give brown thick paste. The residue was purified by silica gel columnchromatography to give 3.30 g (yield 86.8%) compound as a pale yellowsemisolid. ¹H-NMR(CDCl₃, ppm) 0.865(d, J=6.75 Hz, 6H), 1.401(s, 6H),1.448(d, J=6.75 Hz, 6H), 2.85(m, 1H), 3.98(m, 1H), 4.740(s, 2H),6.928(s, 1H), 7.441(s, 1H). MS (m/z) EI⁺: 338/336(1:1, (M-i-Pr)⁺),298/296(M-thexyl)⁺/294, 84(B,C₆H₁₂ ⁺); FAB⁺: 378.2/380.2(M+H)⁺/382.2,336.2/338.2(1:1,(M-i-Pr)⁺), 296.1/298.1(B, M+H—C₆H₁₂), 100.1(t-hexylamine), 85.1(C₆H₁₃ ⁺).

The following biological activity experiments are listed to explain thepresent invention.

Biological activity experiment 1. The effects of 16 compoundsrepresented by formula I on blood pressure, heart rate, cardiaccontraction and dilation in rats anesthetized with pentobarbital sodium.

TABLE 5 The structures and cardiovascular bioactivities of the Compoundsrepresented by formula I in the present invention compound R₁ R₂ R₃ R₄SBP DBP MBP HR LVSP −dp/dtmax Vpm 2 (CH₃)₂CH— CH₃— CH₃— H— 38 15 24 20116 54 1.16 3 (CH₃)₂CH— CH₃— CH₃— CH_(3—) 29 19 22 43 111 157 0.49 4(CH₃)₂CH— CH₃— CH₃— C₂H₅— 31 23 25 44 146 177 0.45 5 (CH₃)₂CH— CH₃— CH₃—n-C₃H₇— 34 25 28 78 162 187 0.58 6 (CH₃)₂CH— CH₃— CH₃— n-C₄H₉— 61 43 49111 263 276 0.98 7 (CH₃)₂CH— CH₃— H— (CH₃)₂CH— 34 34 34 46 184 226 1.088 H— H— H— (CH₃)₂CH— 28 24 26 53 121 124 1.45 9 C₂H₅— CH₃— CH₃—(CH₃)₂CH— 50 36 40 108 260 245 1.68 10 C₂H₅— CH₃— H— H— 2 5 4 20 21 270.25 11 C₂H₅— CH₃— CH₃— CH₃— 18 10 13 19 +159 +86 0.1 12 C₂H₅— CH₃— H—H— 25 23 24 39 112 129 0.58 40 (CH₃)₂CH— CH₃— CH₃— Trp- +2 0 +0.7 6 +23+6 +0.1 41 (CH₃)₂CH— CH₃— CH₃— Ile- +2 +1 +1 16 +4 +2 0 42 (CH₃)₂CH—CH₃— CH₃— Leu- +2 +2 +2 +1 +10 +13 +0.18 43 (CH₃)₂CH— CH₃— CH₃— Phe- +3+1 +2 +10 +31 +10 +0.13 44 (CH₃)₂CH— CH₃— CH₃— O₂N-Arg- +5 +6 +5.7 3 +6+6 +0.07 Notes: The compounds were injected through femoral vein. Doses(mg/kg): 1^(#)(0.5), 2^(#)(10), 3^(#)(5), 4^(#)(5), 5^(#)(5), 6^(#)(5),7^(#)(5), 8^(#)(10), 9^(#)(5), 10^(#)(5), 11^(#)(5), 12^(#)(10),40^(#)(5), 41^(#)(5), 42^(#)(5), 43^(#)(5), 44^(#)(5). SBP: systolicblood pressure; DBP: diastolic blood pressure; MBP: mean blood pressure;HR: heart rate; LVSP: left ventricular systolic pressure; −dp/dt_(max):the maximal rate of the decrease of left ventricular pressure; Vpm: thephysiological velocity of contractile element shorting. Data wereexpressed as mean, n = 3~5. “+” means the increase after administrationand all others mean decrease after administration.

It was suggested that compounds 2˜12 could lower blood pressure ordecrease heart rates, and inhibit cardiac contraction and dilation. Itis reasonable to suggest that these compounds can be used in themanagements for hypertension, blood pressure, tachycardia, anginapectoris and myocardial ischemic diseases. The compounds 40˜44 couldincrease blood pressure and heart rates and improve cardiac contractionand dilation. It is also reasonable to suggest that these compounds canbe used to higher blood pressure and in the managements for shock,bradycardia and congestive heart failure.

The methods of biological activity experiment 1 were as follows: MaleWistar rats, weighing 280±30 g were purchased from the experimentalanimal center of Academy of Military Medical Sciences. Rats wereanesthetized with pentobarbital sodium (45 mg/kg) by peritonealinjection. A PE₅₀ polyethylene catheter was inserted into the leftventricle through right carotid artery for cardiac function measurementwith a pressure energe exchanger, wherein the signal is put into aSMUP-PC biosignal processing system. Cardiac functional parameters suchas HR, LVSP, +dp/dt_(max), −dp/dt_(max) and Vpm were recorded. Anothertwo PE₅₀ polyethylene catheters were inserted into the right femoralartery and vein respectively for blood pressure measurement wherein theartery cathether was linked to a four-channel physiology recorder(RM-6000) through a MPU-0.5A Type pressure energe exchanger, whichrecorded SBP, DBP and MBP, while the vein catheter was used for compoundadministration. The methods were described by Liu Wei et al: Liu Wei,Wang Hai, Xiao Wen-Bin. Effects of pinacidil and nifedipine on cardiacfunctions in rats. Bull Acad Mil Med Sci 1996;20(4):245˜248.

Biological activity experiment 2. The acute antihypertensive effects ofcompound 1 in conscious spontaneously hypertensive rats.

TABLE 6 The effects of compound 1 on systolic blood pressure inspontaneously hypertensive rats. drugs and dose SBP SBP (mmHg) atdifferent time points (h) after administration (mg/kg po) base value 1 35 9 12 24 control 239 ± 11 239 ± 14 238 ± 14 240 ± 9 242 ± 9 243 ± 12245 ± 11 compound 1 3 246 ± 11 227 ± 12*** 218 ± 7*** 215 ± 15*** 229 ±8* 243 ± 7 244 ± 9 pinacidil 3 242 ± 5  208 ± 5*** 236 ± 5* 241 ± 4 242± 5 244 ± 5 244 ± 5 nifedipine 10 242 ± 5  186 ± 6*** 219 ± 12* 235 ± 5240 ± 6 242 ± 4 242 ± 4 bisoprolol 60 242 ± 5  211 ± 7*** 240 ± 7 242 ±4 242 ± 3 243 ± 3 242 ± 6 captopril 40 243 ± 4  207 ± 9*** 213 ± 11**233 ± 10* 242 ± 4 241 ± 5 243 ± 4 Data were expressed as means ± SD for9-13 rats. *p < 0.05, **p < 0.01, ***p < 0.001 vs control, usingself-control t text.

TABLE 7 The effects of compound 1 on heart rates in spontaneouslyhypertensive rats. (mg/kg po) base value 1 3 5 9 12 24 control 402 ± 34405 ± 31 419 ± 15 388 ± 30 393 ± 26 404 ± 32 395 ± 26 compound 1 3 419 ±20 414 ± 27 412 ± 27 408 ± 25 407 ± 21 413 ± 15 417 ± 12 pinacidil 3 351± 19 421 ± 17*** 400 ± 15** 354 ± 14 365 ± 16 352 ± 20 365 ± 15nifedipine 10 352 ± 19 410 ± 11*** 410 ± 31*** 367 ± 24 365 ± 13 365 ±16 364 ± 22 bisoprolol 60 355 ± 17 283 ± 17*** 278 ± 16*** 335 ± 34 320± 36 341 ± 28 360 ± 7 captopril 40 350 ± 17 380 ± 12*** 370 ± 24* 366 ±22* 355 ± 12 355 ± 29 364 ± 12 Data were expressed as means ± SD for9-13 rats. *p < 0.05, **p < 0.01, ***p < 0.001 vs control, usingself-control t test.

The results suggested that oral administration of compound 1 couldinduce antihypertensive actions. The duration of antihypertensive actionlasted 9 hours. At the equivalent doses for producing the sameantihypertensive action, compound 1 had antihypertensive effects oflonger duration and had fewer effects on heart rates, compared withATP-sensitive potassium channel opener pinacidil, calcium antagonistnifedipine, β-blocker bisoprolol and angiotensin converting enzymeinhibitor captopril.

The methods of biological activity experiment 2 were described by LongChao-Liang et al: Long Chao-Liang, Wang Hai, Xiao Wen-Bin. Effects ofpinacidil on, hypertensive vascular remodeling. Chin J Pharmacol Toxicol1997; 11(1):42-46.

Biological activity experiment 3: The antagonism of glibenclamide, aselective ATP-sensitive potassium channel blocker, on the cardiovasculareffects of compound 1 of formula Ia in the present invention.

TABLE 8 The antagonism of glibenclamide on the cardiovascular effects ofcompound 1. Glibenclamide + Pinacidil Pinacidil Nifedipine (n = 8) (n =6) (n = 5) parameters B A B A B A SB (mmHg) 128 ± 5  91 ± 8** 142 ± 7137 ± 4 144 ± 7 104 ± 8*** DBP (mmHg)  92 ± 5  67 ± 6***  95 ± 4  94 ± 3 95 ± 8  62 ± 7*** MBP (mmHg) 104 ± 5  76 ± 7** 110 ± 5 108 ± 3 111 ± 7 76 ± 8*** HR (bpm) 353 ± 17 317 ± 25* 322 ± 14 303 ± 17 335 ± 14 296 ±22 LVSP (mmHg) 124 ± 6 111 ± 9* 127 ± 8 131 ± 5 131 ± 6 113 ± 7***+dp/dtmax (kPa/a) 673 ± 28 571 ± 33* 725 ± 66 766 ± 37 761 ± 38 626 ±57** −dp/dtmax (kPa/a) 536 ± 42 447 ± 73 584 ± 70 602 ± 38 650 ± 26 470± 40*** Vpm (/a)  4.3 ± 0.5  4.1 ± 0.5  6.1 ± 02  6.6 ± 0.1  5.7 ± 0.1 4.2 ± 0.5 Glibenclamide + glibenclamide + nifedipine Compound 1compound 1 (n = 5) (n = 8) (n = 7) parameters B A B A B A SB (mmHg) 136± 4 104 ± 3** 134 ± 8 105 ± 10* 140 ± 6 132 ± 7 DBP (mmHg)  95 ± 6  62 ±4**  98 ± 7  77 ± 9** 115 ± 3 109 ± 4 MBP (mmHg) 108 ± 5  75 ± 3** 110 ±7  86 ± 9** 123 ± 3 116 ± 5 HR (bpm) 308 ± 12 273 ± 16 394 ± 13 357 ± 18368 ± 18 353 ± 21 LVSP (mmHg) 130 ± 10 115 ± 8** 180 ± 10 133 ± 6 151 ±6 139 ± 6 +dp/dtmax (kPa/a) 766 ± 73 649 ± 81* 978 ± 54 672 ± 36*** 803± 51 723 ± 51* −dp/dtmax (kPa/a) 631 ± 88 471 ± 44* 819 ± 56 507 ± 39***595 ± 43 541 ± 24 Vpm (/a)  6.4 ± 0.7  4.2 ± 1.0*  3.3 ± 0.2  2.7 ± 03** 6.1 ± 0.6  5.6 ± 0.5 B: Before administration; A: after administration.Pinacidil (1.0 mg/kg), nifedipine (1.0 mg/kg) and compound 1 (0.5 mg/kg)were administered by iv. Glibenclamide (20 mg/kg) was pretreatment forten minutes by iv. The parameters in Table 8 were measured 30 min afteradministering pinacidil, 10 min after nifedipine and 15 min aftercompound 1 respectively. Data were expressed as means ± SE. Statisticalsignificance between before and after administration was assessed byself-control t test, *p < 0.05, **p < 0.01, ***p < 0.001.

The results suggested that the effects of compound 1 on blood pressure,heart rates and cardiac contraction and dilation could be antagnized byglibenclamide, a selective ATP-sensitive potassium channel blocker.Under the same experimental conditions, glibenclamide could aslo blockthe cardiovascular effects of pinacidil, but had no effects on calciumchannel blocker nifedipine. So compound 1 was revealed to possess thepharmacological properties of ATP-sensitive potassium channelactivators.

The methods of Biological activity experiment 3 were the same as thosedescribed in the biological activity experiment 1.

Biological activity experiment 4. Allosteric regulation of novelcompounds on ATP-sensitive potassium channels in vascular smoothmuscles.

TABLE 9 Effects of compound 1 on the association and dissociationkinetics of [³H]glibenclamide binding to ATP-sensitive potassiumchannels in vascular smooth muscles. concentration Association kinetics(×10⁻²nM⁻¹ · min⁻¹) Dissociation kinetics drugs mol · L⁻¹ = M k_(obs) k₁k_(A) k₂ (×10² nM⁻¹ · min⁻¹) K_(d) (nM) control 4.65 ± 0.37 1.31 ± 0.14181.90 ± 46.90 0.72 ± 0.11 0.55 ± 0.14 compound 1 10⁻⁴ 2.90 ± 0.74* 0.62± 0.25*  61.04 ± 25.89* 1.02 ± 0.14* 1.64 ± 0.69* pinacidil 10⁻⁴ 2.32 ±0.67** 0.39 ± 0.24**  33.91 ± 22.43** 1.15 ± 0.27* 2.95 ± 0.95* ATP 10⁻²7.69 ± 1.01** 2.42 ± 0.34**  590.2 ± 208.20** 0.42 ± 0.14* 0.17 ± 0.06*ADP 10⁻³ 2.28 ± 0.70** 0.45 ± 0.24**  47.80 ± 25.70** 0.94 ± 0.10* 2.09± 1.12* UDP 5 × 10⁻³ 4.26 ± 0.65 1.15 ± 0.23 143.50 ± 49.00 0.80 ± 0.220.70 ± 0.24 Ade 10⁻³ 2.83 ± 0.35* 0.55 ± 0.14*  47.40 ± 14.70** 1.17 ±0.21* 2.11 ± 0.65* Data were expressed as means ± SD, n = 4~10.Statistical significance of differences between data was assessed byANOVA followed by Dunnet's test. *p < 0.05, **p < 0.01.

TABLE 10 Effects of compound 1 on the association kinetics of [³H]P1075binding to ATP-sensitive potassium channels in vascular smooth muscles.concentration Association kinetics drugs (mol · L⁻¹ = M) (k_(obs), ×10⁻²nM⁻¹ · min⁻¹) control 4.36 ± 0.45  Compound 1 10⁻⁴ 2.44 ± 0.80*Glibencamide 10⁻⁵ 3.12 ± 0.17* ATP 10⁻² 2.85 ± 0.08* ADP 10⁻³ 2.63 ±0.48* UDP 5 × 10⁻⁵ 5.53 ± 0.51* GTP 10⁻³ 3.86 ± 0.19  Ade 10⁻³ 3.07 ±0.24* Data were expressed as means ± SD, n = 4~10. *p < 0.05 vs control,statistical significance of differences between data was assessed bygroup t-test.

The binding sites of antagonists and agonists for sulfourea receptors ofATP-sensitive potassium channels in vascular smooth muscles were labeledwith[³H]glibenclamide and [³H] P1075 respectively. As shown in Table 9,compound 1 (100 μmol L⁻¹), pinacidil (100 μmol L⁻¹), ADP (1 mmol L⁻¹)and Ade (1 mmol L⁻¹) could inhibit the association and accelerate thedisassociation of [³H]glibenclamide with ATP-sensitive potassiumchannels in vascular smooth muscles. ATP (10 mmol L⁻¹) could acceleratethe kinetic process of the association and retard the kinetic process ofthe disassociation of [³H]glibenclamide binding with ATP-sensitivepotassium channels in vascular smooth muscles. These results suggestedthat compound. 1 had allosteric effects on the binding sites of theantagonists for ATP-sensitive potassium channels in vascular smoothmuscles. So compound I had the same activity as pinacidil, but contraryto that of ATP. As shown in Table 10, compound 1 (100 μmol L⁻¹),glibenclamide (10 μmol L⁻¹), ATP (10 mmol L⁻¹), ADP (1 mmol L⁻¹) and Ade(1 mmol L⁻¹) all inhibited the kinetic process of the association of[³H]P1075 binding with ATP-sensitive potassium channels, while UDPaccelerated the kinetic association process. These results suggestedthat compound 1 also had allosteric effects on binding sites of theagonists for ATP-sensitive potassium channels in vascular smoothmuscles. It was the same as that of glibenclamide, ATP, ADP and Ade, butcontrary to that of UDP.

To study the allosteric regulation of compound 1 on ATP-sensitivepotassium channels in vascular smooth muscles, the radio-labled-ligandwas used in the biological activity experiment 4.

1. The allosteric regulation of compound 1 on the binding sites for theselective K_(ATP) blocker glibenclamide in vascular smooth muscles wasstudied as follows: After decapitated, the male Wistar rat (340±20 g)was immediately incised open the thoracic cavity. The aorta wasdissected and immersed in the 4° C. buffer containing 10 mM HEPES towash off the blood, then carefully extirpated the fat, peripheralconnective tissues and thrombus. The aorta was cut into about 3-5 mmarterial rings and the vascular endothelium was scraped off with wettampon. The arterial rings were blotted, weighted and transferred intothe tubes containing proper amount of ice colded physiological salinebuffer. In the association kinetics experiment, the arterial circles inthe tubes were incubated with, compound 1(10⁻⁴M), pinacidil(10⁻⁴M),ATP(10⁻²M), ADP(10⁻³M), Ade(10⁻³M), ADP(5×10⁻⁵M) and equal volume ofbuffer respectively for 10 min in 25° C. water bath, and then added[³H]-glibenclamide(3 nM). At 5,10,15,20,30,60,90 and 120 min afterincubation, 9 mL ice colded Tris buffer (50 mM) was added to terminatethe reaction. After washing off the free and bound [³H]-glibenclamide,the aorta was blotted, transferred to a scintillator, added 50 uL 30%H₂O₂ and reacted for 2 h at 80° C. After cooling, 2.5 mL ethyl glycoland 5 mL 1% B-BPD xylene were added in sequence, kept stationary for 8 hand measured under a scintillometer for cpm value. The resulting datawere fit into a regression line with In[B_(EQ)/(B_(EQ)-B_(t))]vs.t andthe parameters for association kinetics were obtained. In thedisassociation kinetics experiments, the aorta treated as describedabove and [³H]-glibenclamide were incubated for 60 min at 25° C., andthen 30 uM glibenclamide was added. 0,5,15,30,60,90 and 120 min later,the cpm values for the complex of [³H]-glibenclamide and K_(ATP) weremeasured. The resulting data were fit into a regression line withIn(B/B_(EQ))]vs.t and the parameters for disassociation kinetics wereobtained.2. The allosteric regulation of compound 1 on the binding sites for theselective K_(ATP) activator P1075 in vascular smooth muscles was studiedwith the method as described above, but some conditions should bechanged as follows: the incubation temperature was 37° C. instead of 25°C.;P1075 was used instead of glibenclamide; In the association kineticsexperiments, the time points for sampling were 5,10,15,20,30,45,60 and90 min, while in the disassociation kinetics experiments, that were1,3,5,10,20,30,45 and 60 min.Biological activity experiment 5. The effects of compound 1 on thespecific binding of high selective activator [³H]P1075 withATP-sensitive potassium channels in vascular smooth muscles.

As shown in FIG. 1, endothelium-removed smooth muscle samples derivedfrom rat aorta were incubated with non-labeled P1075 and [³H] P1075 (5nmol L⁻¹) for 90 minutes at 37° C. P1075 could inhibit the specificbinding of [³H]P1075 in a concentration-dependent manner, of which theIC₅₀ value was 9.1±1.3 nmol L⁻¹, and pKi value was 8.04±0.88. Under thesame experimental conditions, pinacidil, compound 1 and glibenclamidealso could inhibit the specific binding of [³H]P1075 in aconcentration-dependent manner. The IC₅₀ values were 199.5±43.6 nmolL⁻¹, 354.8±53.7 nmol L⁻¹ and 58.9±4.6 μmol L⁻¹ respectively and the pKivalues were 6.70±0.36, 6.45±0.73 and 4.23±2.34 respectively. Thecompetitive inhibition effects of compound 1 on the binding of [³H]P1075 was 39 times weaker than that of P1075 and 1.8 times weaker thanthat of pinacidil, but was 166 times stronger than that ofglibenclamide. Compound 1 could displace [³H]P1075 in the specificbinding with sulfourea receptor of vascular smooth muscles in aconcentration-dependent manner. The affinity of compound 1 with thebinding site for ATP-sensitive potassium channel opener was similar withthat of pinacidil.

The method of biological, activity experiment 5 was carried out asfollows: After the male Wistar rat (350±46 g) was decapitated, the aortawas dissected out and then immersed in the buffer containing 5 mM HEPESat 4° C., carefully extirpated the outer tissue, capillary vessel andblood. After that, the aorta was cut into about 5-7 mm arterial ringswith wet weight 5-7 mg and the vascular endothelium was removedmechanically. After weighted, the arterial rings were transferred intothe tubes containing buffer.

The different tubes were all added the aorta sample (5-7 mg) and[³H]P1075(5 nM), then added different concentration of potassium channelblockers (glibenclamide), potassium channel opener (pinacidil andP1075), compound 1, non-labled P1075(50 uM) and HEPES buffer (5 mM)respectively, at last added buffer to 250 uL. The reaction mixture wasstired and incubated for 90 min at 37° C., then measured cpm value.

The experimental protocol were described in details in the publication:Bray K M, Quast U. A specific binding site for K⁺ channel openers in rataorta. J Biol Chem, 1993; 267(17):11689-92.

Biological activity experiments 6. The effects of novel compounds onpotassium currents in isolated arterial vascular smooth muscle cells(SMCs).

TABLE 11 The chemical structures of the compounds and their effects onthe outward potassium currents of rat tail arterial SMCs. Currents (nA)Control + Compound Compound R₁ R₂ R₃ R₄ X ± SD n = 5 1 (CH₃)₂CH— CH₃—CH₃— (CH₃)₂CH— 0.41 ± 0.08  119.3 ± 10.9** 2 (CH₃)₂CH— CH₃— CH₃— H— 0.91± 0.49 1.01 ± 0.57 3 (CH₃)₂CH— CH₃— CH₃— CH₃— 0.56 ± 0.31 0.60 ± 0.34 4(CH₃)₂CH— CH₃— CH₃— C₂H₅— 0.61 ± 0.12  0.69 ± 0.14** 5 (CH₃)₂CH— CH₃—CH₃— CH₃CH₂CH₂— 0.65 ± 0.30 0.67 ± 0.30 6 (CH₃)₂CH— CH₃— CH₃— n-C₄H₉—0.49 ± 0.23  1.18 ± 0.54* 13 (CH₃)₂CH— CH₃— CH₃— (CH₃)₂CHCH₂— 0.55 ±0.34  0.85 ± 0.31** 15 (CH₃)₂CH— CH₃— CH₃—

0.83 ± 0.24  1.30 ± 0.45* 24 (CH₃)₂CH— CH₃— CH₃— PhCH₂— 0.65 ± 0.19 0.63± 0.19 25 (CH₃)₂CH— CH₃— CH₃— CH₂═CH—CH₂— 0.68 ± 0.19  1.46 ± 0.50** 39(CH₃)₂CH— CH₃— CH₃—

0.46 ± 0.14 0.51 ± 0.22

The outward currents were, elicited in rat tail arterial SMCs bysuperfusing extracellular solution under whole cell recordingconfiguration that the depolarizing pulse were applied from −30 mV to+100 mV with the holding potential of −40 mV in 100 ms, 10 mV clampsteps, a frequency of 5 KHz. The compounds were applied in the bath atthe concentrations of 100 μmol L⁻¹. The amplitude of the outwardpotassium currents was recorded before and after compound applicationValues were expressed as means±SD. Statistical significance between twogroups was evaluated by student's t-test for paired data * P<0.05**P<0.01 vs control.

The results indicated that the compounds with different types of sidechain R4 displayed differing abilities to promote potassium currents interms of structure-activity relationships. These compounds with sidechain R4 of isopropyl, ethyl, butyl; 1-methylpropyl, cyclopropylmethyl,allyl respectively, showed a powerful stimulation of potassium channelactivities. Maximum potency was displayed by compound 25. While thesecompounds with side chain of hydrogen, methyl, propyl, benzyl,2-pyridylformacyl respectively, displayed very slight activities, whichwere not statistically significant.

Effects of Compound 1 on Potassium Currents in Isolated Intrapulmonaryarterial SMCs and Glibenclamide Antagonism

The outward potassium currents were recorded in smooth muscle cellsderived from intrapulmonary arteries of normotensive rats. Cells weresealed, clamped at −70 mV and depolarized to +50 mV at an increasingstep of 10 mV with 100 ms duration. After application of compound 1 atthe concentration of 10 μmol L⁻¹, the amplitude of the currents in 5/8cells was increased to 115.4±2.8% compared with control recorded beforecompound application (P<0.01 n=5). While in the presence of bothcompound 1 and glibenclamide at the concentration of 10 μmol L⁻¹ and 30μmol L⁻¹ respectively, the amplitude of the outward potassium currentsin 7/7 cells was detected to be 83.1±8.3% of control, which wasdecreased compared with the presence of compound 1 only (P<0.01 n=7).The corresponding potassium current-voltage curves (I-V curves) wereshowed in FIG. 2.

These results suggested that the conpound 1 could enhance the outwardpotassium currents but these effects could be antagonized byglibenclamide, a specific blocker of adenosine triphosphate(ATP)-sensitive potassium channels. So it could be said that compound 1possessed the pharmacological properties of ATP-sensitive potassiumchannel activators.

Method of Bioactive Experiment 6:

1. Preparation of single smooth muscle cells from rat tail arteries:Male Wistar rats (200-250 g) were killed by exsanguination. The tailartery was dissected out and transferred into cold physiological saltsolution (PSS) of the following composition (in mM): NaCl 118.3, KCl4.7, KH₂PO₄ 1.2, MgSO₄ 1.2, NaHCO₃ 25.0, CaCl₂ 2.5, EDTA 0.026 andGlucose 5.0 pH7.4. With the use of a dissecting microscope, theconnective tissues were removed and the artery was cut openlongitudinally. Endothelium was removed carefully with a cotton swabthen the artery was cut into segments with 1 mm long and placed in 4° C.the extracellular solution containing (in mM) NaCl 130, KCl 5, MgCl₂1.2, HEPES 10, Glucose 10, pH7.2 for 20 min. After this incubation, themedium was changed to enzyme solution which was composed of collagenaseI (1 mg ml⁻¹), papain (5 mg ml⁻) and bovine serum albumin (2 mg ml⁻¹).The tissues, were incubated in this solution for 40 min, and then rinsedthree times triturated using a fire-polished Pasteur pipette until themedium turned cloudily. The cell suspension was stored in therefrigerator at 4° C.

2. Preparation of smooth muscle cells from intrapulmonary arteries: MaleWistar rats were killed by decapitation. The intrapulmonary arterieswere isolated and moved quickly into physiological salt solutions (PSS,4° C.) Then the arteries were cut longitudinally and cut into smallsegments after scraping off the endothelium gently with a cotton swab.The fragments were then incubated at 37° C. in Ca²⁺-free PSS for 20 to30 minutes. This was followed by 58 minutes digestion at 37° C. inisolation solution containing: 2 mg ml⁻¹ bovine serum albumin, 1 mgml⁻¹collagenase I 5 mg ml⁻¹papain, 1.25 mol L⁻¹ dithiothreitol and 16μmol L⁻¹ Ca²⁺. Next, the softened vessel segments were transferred toCa²⁺-free PSS and rinsed three times. The isolated single cells weregentle agitated with a polished glass pipette.

3. Whole cell recordings: A bath dish with the smooth muscle cells(SMCs) attached and superfused with the extracellular solution at a flowrate of 2 ml min⁻¹ was mounted onto the stage of an inverted-phasecontrast microscope. The microelectrodes having a resistance of (5-8 MΩ)were made from boroscilicate thin-wall glass capillaries, using anautomatic multiple-stage, electronic puller (PP830 Japan) and thenheat-polished. After establishing a high resistance seal, the patchmembrane was disrupted by negative pressure. A commercial patch clampamplifier (Axon 200B) was used to generate and apply voltages and samplecurrent signals from the cell.

Biological Activity Experiment 7 The Protective Effects of compound 1 onPan-Cerebral Ischemia-Reperfusion Injury in Jirds

As shown in FIG. 3, HE staining revealed that pan-cerebral ischemiadecreased significantly the number of normal pyramidal nerve inhippocampal CA1 region of jirds. The mean number was only 15% of that ofthe control. Compound 1 could significantly decreased the number of deadpyramidal nerve of hippocampal CA1 region in jirds caused bypan-cerebral ischemia in a dosage-dependent manner (0.5-4.0mg.kg⁻¹.d⁻¹;ip), and increase the number of normal pyramidal nerve. Itsuggested that compound 1 could significantly reverse ischmic nerveinjure.

As shown in FIG. 4, enzyme-linked immunochemistry TUNEL revealed that innegative control group, the nucleus and cytoplasm of pyramidal nerve ofhippocampal CA1 region in jirds were not stained, while in positivecontrol group, the nucleus was stained, which confirmed the methods usedin this study, were credible. Pan-cerebral ischemia greatly increasedthe number of apoptosized pyramidal nerve of hippocampal CA1 region injirds, while compound 1 could significantly alleviate the apoptosis ofpyramidal nerve of hippocampal CA1 region induced by pan-cerebralischemia in a dosage-dependent manner. It suggested that compound 1could significantly reverse ischemic nerve apoptosis.

The methods of biological activity experiment were carried out asfollows: equal amounts of male and female jirds (60-70 g) were subjectedto bilateral cervical aorta occlusion (BCAO) under narcotism. The drugsor equal amounts of physiological saline solution were injectedperitoneally at 30 min before occlusion. After the blood flow in thebilateral cervical aorta was blocked for 5 min, reperfusion was restoredand the drug was administered once a day for 7 days. During the BCAO,the body temperature was maintained at 37° C. In the control group, thecervical aorta was only exposed, while not blocked for blood flow. Theanimals were divided in 6 groups randomly: control group, ischemic groupand compound-treated group (0.5, 1.0, 2.0 and 4.0 mg.kg⁻¹, ip). 7 daysafter BCAO, the animals were deeply anesthetized by injectingperitoneally 80 mg.kg⁻¹ pentobarbitol sodium, and perfused with 50 mLphysiological saline solution and 4% paraformaldehyde through heart. Thebrain was dissected, immersed in 4% paraformaldehyde for 24 h,dehydrated, cleared, embedded with paraffin, sectioned and stained withHE. TUNEL staining was employed to detect the nerve apoptosis.

Biological activity experiment 8 the prophylaxis and treatment ofcerebral apoplexy with compound 1 of formula I_(a)

TABLE 12 The effects of compound 1 on the rate and period needed foronset of SHR_(sp) cerebral apoplexy Rate of cerebral group n apoplexy(%) Period (d) control 12 83.3 48.3 ± 7.4   Compound 1 (0.25 mg · 1272.7 58.6 ± 14.1*  kg⁻¹d⁻¹) Compound 1 (1 mg · kg⁻¹d⁻¹) 12 40.0* 60.8 ±18.9*  Compound 1 (4 mg · kg⁻¹d⁻¹) 12 33.3* 68.6 ± 16.5** Nimodipine (40mg · kg⁻¹d⁻¹) 12 36.4* 66.0 ± 14.8** The data were expressed as means ±SD; *p < 0.05, **p < 0.01 vs control, group t-test.FIG. 5 The effects of compound 1 on grade value of nerve symptom ofSHR_(sp) cerebral apoplexy.

TABLE 13 The effects of compound 1 on death rate and survival timeduring SHR_(sp) cerebral apoplexy Death rate of cerebral Survival groupn apoplexy (%) time (d) control 12 50.0 4.6 ± 3.8 Compound 1 (0.25 mg ·12 27.3 7.2 ± 5.3 kg⁻¹d⁻¹) Compound 1 (1 mg · kg⁻¹d⁻¹) 12 20.0 10.2 ±4.1* Compound 1 (4 mg · kg⁻¹d⁻¹) 12 8.3* 11.8 ± 3.2* Nimodipine (40 mg ·kg⁻¹d⁻¹) 12 9.1* 11.1 ± 2.7* The data were expressed as means ± SD; *p <0.05 vs control, group t-test.

The results showed that compound 1 and nimodipine could significantlydecrease the rate of cerebral apoplexy and delay the onset of cerebralapoplexy, significantly improve the nerve symptom of cerebral apoplexy,and significantly lower the death rate of cerebral apoplexy and longerthe animal's survival time.

The methods of biological activity experiments were carried out asfollows: Desired concentration of compound 1 was prepared with distilledwater, while desired concentration of nimodipine was prepared withmarket available Jinglongyu^(T) oil. 30 male and 30 female SHR_(sp) (10weeks old, 120-180 g) were purchased from the vascular disease researchcenter of Academy of Military Medical Science. All SHRsp were dividedrandomly into five groups based on blood pressure, body weight and sex:control group (fed with equal amount of Jinglongyu^(T) oil), 0.25mg.kg⁻¹d⁻¹ compound 1 treated group, 1.0 mg.kg⁻¹d⁻¹ compound 1 treatedgroup, 4.0 mg.kg⁻¹d⁻¹ compound 1 treated group, and 4.0 mg.kg⁻¹d⁻¹nimodipine treated group. Each group contained 12 animals and 4-5animals were fed in a cage. The feedstaff (containing 23-24% protein)was purchased from experimental animal center of Academy of MilitaryMedical Science. The animals were fed with tap water containing 1% NaClto accelerate the onset of cerebral apoplexy. 12 normal WKY rats (withthe same age and sex with the above) were selected as control, and fedwith tap water and the same feedstuff. When reached 11 weeks old, theanimals were fed with drugs for experiments.

Biological Activity Experiment 9 The Inhibition Effects of Compound 1 onthe Cordical Nerve Apoptosis Induced by Low Level Oxygen and Glucose

As shown in FIG. 6, the electron microscopy was used to observe thecordical nerve apoptosis induced by low level oxygen and glucose and theeffects of compound 1 thereon. The chromatin distributed equably innormal cordical nerve cells and the cell membrane remained intact.However, in low level oxygen and glucose treated group, the cells weresmaller, the chromatin was condensed, ruptured and distributed near thenuclear membrane, wherein some chromatin formed circle or crescent, andin late stage the cell membrane emboled and enwrapped the chromatinfragments to form apoptosis body. In 10 umol.L⁻¹ compound 1 treatedgroup, the above mentioned changes were hardly observed. Moreover, thechromatin condensation decreased, and the nuclear membrane and cellmembrane maintained intact. Therefore, the said concentration ofcompound 1 had the effects against the cordical nerve cell apoptosisinduced by low level oxygen and glucose.

FIG. 7 showed the apoptosis percentage of cordical nerve induced by lowlevel oxygen and glucose (under the flow cytometer). The cells were PIstained and the cells at different stages were measured for DNA contentby the flow cytometer. In control group, most nerve cells were at G₁stage and the apoptosis percentage was about 2.3%. In low level oxygenand glucose treated cells, G₁ sub-peak occurred at 8, 16 and 24 h, andthe apoptosis percentage were 13.6±5.8%, 23.8±7.4% and 20.3±7.1%. Theapoptosis was most significant at 16 h.

TABLE 14 The effects of compound 1 on the apoptosis percentage ofcordical nerve induced by low level oxygen and glucose Apoptosis grouppercentage (%) Control  2.3 ± 1.2 Low level oxygen and glucose treated23.8 ± 7.4* 0.1 umol · L⁻¹ compound 1 treated 17.6 ± 5.8   1 umol · L⁻¹compound 1 treated 13.9 ± 5.2^(#)  10 umol · L⁻¹ compound 1 treated 10.8± 4.1^(##) The data were expressed as means ± SD; *p < 0.01, vs controlgroup; ^(#)p < 0.05, ^(##)p < 0.01, vs low level oxygen and glucosetreated group.

The results showed that compound 1 could inhibit the cordical nerveapoptosis induced by low level oxygen and glucose in a dosage-dependentmanner.

The methods of biological activity experiment 9 were carried out asfollows: The cordical nerve were prepared from 12-hour old Wistar ratsand cultured. See G. Y. Yang, A. L. Bentz. Reperfusion-induced injure tothe blood-brain after middle cerebral artery occlusion in rats. Stroke,1994,25:1658-1665. Serum-free DMEM medium was applied 12 days later. Thepreparation was incubated in low oxygen tank (95% N₂+5% CO₂) for 8, 16and 24 h respectively, and then restored oxygen to normal level foranother 24 h. The experiments on five groups were as follows: thecontrol group was cultured for 14 days with normal medium; low leveloxygen and glucose treated group was cultured with normal medium for 12days, then with serum-free medium containing low level oxygen andglucose for 16 h and with normal oxygen level for another 24 h; compound1 treated group was cultured in serum-free medium containing low leveloxygen and glucose for 16 h and with normal oxygen level for another 24h, then added respectively different concentrations of compound 1 (0.1,1.0 and 10 umol.L⁻¹). As to the method for detecting apoptosis by theelectron microscopy and flow cytometer, refer to C.Du, R.Hu, C. A.Csernansky, et al. Very delayed infarction after mild focal cerebralischemia: a role for apoptosis. J.Cereb.Flow Metab., 1996,16:195-201;M.Chopp, Y.Li, N.Jiang, et al. Antibodies against adhesion moleculesreduced apoptosis after transient middle artery occlusion in rat brain.J.Cereb.Flow Metab., 1996,16:578-584.

1. An amine derivative represented by formula I_(a),

its racemes or optical isomers, its pharmaceutical acid addition saltsor its amides or esters, wherein, (1) when R′₁ is isopropyl and each ofR′₂ and R′₃ represents methyl, R′₄ may be isopropyl, n-butyl, isobutyl,t-butyl, cyclopropylmethyl, allyl, dimethylaminoethyl, diisopropyllaminoethyl; or (2) when each of R′₁ and R′₂ represents methyl,R′₃—C—NH—R′₄ may be an amine derivative represented by following formulaI′_(a),

racemes or optical isomers thereof, wherein each of R and R′ representsC₁₋₅ hydrocarbyl, n represents an integer of one to eight; or when R′₁represents H₂NC(CH₃)₂—, and each of R′₂ and R′₃ represents methyl, R′₄represents isopropyl; or when R′₁ represents HOC(CH₃)₂—, and each of R′₂and R′₃ represents methyl, R′₄ represents (CH₃)₂CH—or (CH₃)₂CH(CH₃)—; orwhen R′₁ represents 1-hydroxylcyclohexyl, and each of R′₂ and R′₃represents methyl, or R′₂ and R′₃ together represent —(CH₂)₄₋ or(CH₂)₅—, R′₄ represents (CH₃)₂CH—; or when R′₁ represents O₂NOC(CH₃)₂—,and each of R′₂ and R′₃ represents methyl, R′₄ represents (CH₃)₂CH—; orwhen R′₁ represents

and each of R′₂ and R′₃ represents methyl, or R′₂ and R′₃ togetherrepresent —(CH₂)₄—or (CH₂)₅—, R′₄ represents (CH₃)₂CH—; or when R′₁represents

and each of R′₂ and R′₃ represents methyl, R′₄ represents (CH₃)₂CH—or(CH₃)₂CH(CH₃)—; or when R′₁ represents

and each of R′₂ and R′₃ represents (CH₂)₅—, R′₄ represents(CH₃)₂CCH(CH₃)—; or (4) when R′₁ represents cyclohexyl, and each of R′₂and R′₃ represents methyl, R′₄ may represent

or when R′₁ represents cyclopentyl, and R′₂ and R′₃ both represent—(CH₂)₂—, R′₄ may represent

or when R′₁ represents isopropyl, and each of R′₂ and R′₃ represents

methyl, R′₄ may represent

or (5) when R′₁ represents isopropyl, and each of R′₂ and R′₃ representsmethyl, R′₄ may represent Val-, Trp-, lle-, Leu-, Phe-, O₂N-Arg-, Pro-,Leu-Val-, Trp-Trp-Trp- or (CH₃)₂ CH—SO₂—; or R₄′ may represent tosyl,nicotinyl, 4-chlorobenzoyl, morphorinoacetyl, 3-thienylacetyl, or3-indotylacetyl; or when R′₁ represents cyclopropyl, and each of R′₂ andR′₃ represents —(CH₂)₂—, R′₄ represents Val-; or when R′₁ representscyclohexyl, and each of R′₂ and R′₃ represents methyl, R′₄ representsPro-; or when R′₁ represents cyclohexyl, and each of R′₂ and R′₃represents —(CH₂)₂—, R′₄ represents Pro- or nicotinyl.
 2. An aminederivative of claim 1, which may be selected from the group consistingof following compounds: N-(1-methylethyl)-2,3-d imethyl-2-butylamine;N-propyl-2,3-dimethyl-2-butylamine;N-(2-methylpropyl)-2,3-dimethyl-2-butylamine;N-cyclopropylmethyl-2,3-dimethyl-2-butylamine;N-allyl-2,3-dimethyl-2-butylamine; N-{2-[di-(1-methylethyl)amino]ethyl}-2,3-dimethyl-2-butylamine;N-butyl-2,3-dimethyl-2-butylamine; N-propyl-α-methylphenylpropylamine;N-propyl-α,β-dimethyl-phenylpropylamine;N-(3-pyridyl)formyl-2,3-dimethyl-2-butylamine;N-valyl-2,3-dimethyl-2-butylamine;N-tryptophyl-2,3-dimethyl-2-butylamine;N-(N-nitro)arginyl-2,3-dimethyl-2-butylamine;N-phenylalanyl-2,3-dimethyl-2-butylamine;N-leucyl-2,3-dimethyl-2-butylamine;N-isoleucyl-2,3-dimethyl-2-butylamine;N-tosyl-2,3-dimethyl-2-butylamine;N-(1-methylethyl)-2,3-dimethyl-3-hydroxy-2-butylamine;N-cinnamoyl-N-(1-methylethyl)-2,3-dimethyl-2-butylamine;N-(1-methylethyl)-N-(2,4,5-trichlorophenoxyacetyl)-2,3-dimethyl-2-butylamine.
 3. The amine derivative of claim 1, wherein thepharmaceutical acid addition salts may be hydrochloride, sulfate,phosphate, hydrobromide; or acetate, oxalate, citrate, gluconate,succinate, tartarate, tosylate, methanesulfonate, benzoate, lactate ormaleate.
 4. The amine derivative of claim 1, wherein said compound isN-(1-methylethyl)-2,3-dimethyl-2-butylamine tosylate.
 5. A method forpreparation of an amine compound of formula I_(a) as defined in claim 1,which includes the following steps: the solution of the primary amineR′₁R′₂R′₃CNH₂ and R′₄X in an organic solvent is heated to 50-300° C.and/or pressurized to 0.1-20 million pascal, wherein R′₁, R′₂, R′₃ andR′₁ are defined as in claim 1, X is a leaving group, characterized inthat the primary amine R′₁ R′₂R′₃CNH₂ is produced by the followingmethod: (1) the mixture of urea, alcohol or alkene of R′₁R′₂R′₃C or amixture of the both, and concentrated sulfuric acid is heated to 20-200°C. in the presence of an organic acid to yield the hydrocarbylureaR′₁R′₂R′₃C NHCONH₂; and (2)-the hydrocarbylurea is hydrolyzed to givethe corresponding primary amine, wherein said organic acid is selectedfrom acetic acid, trifluoroacetic acid or methanesulfonic acid.
 6. Themethod of claim 5, wherein the reaction of the primary amine with R′₄Xis carried out in the presence of a catalyst, and the catalyst may be adeacidifying agent and/or a phase transfer catalyst.
 7. The method ofclaim 6, wherein the deacidifying agent is a Lewis base, and the phasetransfer catalyst is glycol or polyglycol.
 8. The method of claim 5,wherein the organic solvent is toluene, xylene, 1,2-dichloroethane,1,4-dioxane, dimethoxyethane, N,N-dimethylformide,N,N-dimethylacetamide, N-methylpyrrolidone, N,N-dimethylaniline, orN,N-diethylaniline.
 9. A pharmaceutical composition, comprising at leastan amine derivative represented by formula Ia or formula I, its racemesor optical isomers, its pharmaceutical acid addition salts or its amidesor esters as claimed in any one of claims 1-4, and a pharmaceuticalcarrier or excipient.